Upgraded to DeprecationWarning on ext `config` keyword.

Also checked for `None` so the existing extensions will at least still work.
Of course, that code all gets deleted with the next release and things will
break if extension authors do not update their code. Hope they test there
code with each release and check for warnings.

Also added a note to the release notes.

2 files changed, 68 insertions, 18 deletions

diff --git a/docs/release-2.6.txt b/docs/release-2.6.txt
index 209d0c3..783837e 100644
--- a/docs/release-2.6.txt
+++ b/docs/release-2.6.txt
@@ -53,7 +53,7 @@ Backwards-incompatible Changes
     all except the `text` argument on the `markdown.markdown()` wrapper function.
     Using positional arguments will raise a **`DeprecationWarning`** in 2.6 and an error
     in version 2.7. Only keyword arguments should be used. For example, if your code
-    previosuly looked like this:
+    previously looked like this:
 
         html = markdown.markdown(text, [SomeExtension()])
     
@@ -65,11 +65,11 @@ Backwards-incompatible Changes
         This change is being made as a result of deprecating `"safe_mode"` as the 
         `safe_mode` argument was one of the positional arguments. When that argument 
         is removed, the two arguments following it will no longer be at the correct 
-        position. It is recomended that you always use keywords when they are supported
+        position. It is recommended that you always use keywords when they are supported
         for this reason.
 
-* In previous versions of Python-Markdown, the builtin extensions received
-  special status and did not require the full path to be provided. Additionaly,
+* In previous versions of Python-Markdown, the built-in extensions received
+  special status and did not require the full path to be provided. Additionally,
   third party extensions whose name started with "mdx_" received the same 
   special treatment. This behavior is deprecated and will raise a
   **`DeprecationWarning`** in version 2.6 and an error in 2.7. Ensure that you
@@ -86,7 +86,7 @@ Backwards-incompatible Changes
 
         $ python -m markdown -x markdown.extensions.extra input.txt
 
-    See the [documentation](reference.html#extensions) for a full explaination
+    See the [documentation](reference.html#extensions) for a full explanation
     of the current behavior.
 
 *   The previously documented method of appending the extension configs as 
@@ -94,7 +94,7 @@ Backwards-incompatible Changes
     **`DeprecationWarning`** in version 2.6 and an error in 2.7.
     The [extension_configs](reference.html#extension_configs) keyword should 
     be used instead. See the [documentation](reference.html#extension-configs) 
-    for a full explaination of the current behavior.
+    for a full explanation of the current behavior.
 
 *   The [HeaderId][hid] Extension is pending deprecation and will raise a
     **`PendingDeprecationWarning`** in version 2.6. The extension will be
@@ -109,11 +109,59 @@ Backwards-incompatible Changes
 
 [hid]: extensions/header_id.html
 
+*   Positional arguments and the `configs` keyword on the `markdown.extension.Extension` class
+    (and its subclasses) are deprecated. Each individual config option should be passed
+    to the class as a keyword/value pair. For example. one might have previously initiated
+    an extension subclass like this:
+
+        ext = SomeExtension(configs={'somekey': 'somevalue'})
+
+    That code should be updated to pass in the options directly:
+    
+        ext = SomeExtension(somekey='somevalue')
+    
+    Extension authors will want to note that this affects the `makeExtension` function as well.
+    Previously it was common for the function to be defined as follows:
+    
+        def makeExtension(configs=None):
+            return SomeExtension(configs=configs)
+
+    Extension authors will want to update their code to the following instead:
+
+        def makeExtension(**kwargs):
+            return SomeExtension(**kwargs)
+
+    Failing to do so will result in a DeprecationWarning and will raise an error in the next
+    release. See the [Extension API][mext] documentation for more information.
+
+    In the event that an `markdown.extension.Extension` subclass overrides the `__init__` method
+    and implements its own config handling, then the above may not apply. However, it is
+    recommended that the subclass still calls the parent `__init__` method to handle configs
+    like so:
+    
+        class SomeExtension(markdown.extension.Extension):
+            def __init__(**kwargs):
+                # Do pre-config stuff here
+                # Set config defaults
+                self.config = {
+                    'option1' : ['value1', 'description1'],
+                    'option2' : ['value2', 'description2']
+                }
+                # Set user defined configs
+                super(MyExtension, self).__init__(**kwargs)
+                # Do post-config stuff here
+
+    Note the call to `super` to get the benefits of config handling from the parent class.
+    See the [documentation][config] for more information.
+
+[config]: extensions/api.html#configsettings
+[mext]: extensions/api.html#makeextension
+
 What's New in Python-Markdown 2.6
 ---------------------------------
 
 *   Official support for [PyPy] has been added. While Python-Markdown has most likely
-worked on PyPy for some time, it is now offically supported and tested on PyPy.
+worked on PyPy for some time, it is now officially supported and tested on PyPy.
 
 [PyPy]: http://pypy.org/
 
@@ -129,7 +177,7 @@ worked on PyPy for some time, it is now offically supported and tested on PyPy.
 [YAML]: http://yaml.org/
 
 *   The [Table fo Contents][TOC] Extension has been refactored and some new features
-    have been added.  See the documentation for a full explaination of each feature
+    have been added.  See the documentation for a full explanation of each feature
     listed below:
 
       * The extension now assigns the Table of Contents to the `toc` attribute of
@@ -150,7 +198,7 @@ worked on PyPy for some time, it is now offically supported and tested on PyPy.
   
       * A `baselevel` config option has been added allowing users to set the base level
         of headers in their documents (h1-h6). This allows the header levels to be
-        automatically adjusted to fit within the hierarchy of an html template.
+        automatically adjusted to fit within the hierarchy of an HTML template.
 
 [TOC]: extensions/toc.html
 
diff --git a/markdown/extensions/__init__.py b/markdown/extensions/__init__.py
index a823fef..6e7a08a 100644
--- a/markdown/extensions/__init__.py
+++ b/markdown/extensions/__init__.py
@@ -26,25 +26,27 @@ class Extension(object):
         # check for configs arg for backward compat.
         # (there only ever used to be one so we use arg[0])
         if len(args):
-            self.setConfigs(args[0])
+            if args[0] is not None:
+                self.setConfigs(args[0])
             warnings.warn('Extension classes accepting positional args is '
                           'pending Deprecation. Each setting should be '
                           'passed into the Class as a keyword. Positional '
-                          'args will be deprecated in version 2.6 and raise '
+                          'args are deprecated and will raise '
                           'an error in version 2.7. See the Release Notes for '
-                          'Python-Markdown version 2.5 for more info.',
-                          PendingDeprecationWarning)
+                          'Python-Markdown version 2.6 for more info.',
+                          DeprecationWarning)
         # check for configs kwarg for backward compat.
         if 'configs' in kwargs.keys():
-            self.setConfigs(kwargs.pop('configs', {}))
+            if kwargs['configs'] is not None:
+                self.setConfigs(kwargs.pop('configs', {}))
             warnings.warn('Extension classes accepting a dict on the single '
                           'keyword "config" is pending Deprecation. Each '
                           'setting should be passed into the Class as a '
-                          'keyword directly. The "config" keyword will be '
-                          'deprecated in version 2.6 and raise an error in '
+                          'keyword directly. The "config" keyword is '
+                          'deprecated and raise an error in '
                           'version 2.7. See the Release Notes for '
-                          'Python-Markdown version 2.5 for more info.',
-                          PendingDeprecationWarning)
+                          'Python-Markdown version 2.6 for more info.',
+                          DeprecationWarning)
         # finally, use kwargs
         self.setConfigs(kwargs)