using a more portable **exception_kwargs collection
- added "source" member to the dict propigated to Lexer/Compile exceptions
- RichTraceback can access original template source as a unicode object
using either 'source' memebr on Lexer/Compile exception, or 'source'
property on ModuleInfo, fixes #37
- unit tests for #37

  allows much simpler and hopefully bug-free tracking of 'caller',
  fixes #28
- if plain Python defs are used with <%call>, a decorator
  @runtime.supports_callable exists to ensure that the "caller"
  stack is properly handled for the def.

  [ticket:34]

via <%page> or default_filters (but not those within the filter)
- added buffer_filters argument, defines filters applied to the return value
of buffered/cached/filtered %defs, after all filters defined with the %def
itself have been applied.  allows the creation of default expression filters
that let the output of return-valued %defs "opt out" of that filtering
via passing special attributes or objects.
- added support for "class" structures in ast parsing (i.e. class-level
data members wont get added to the "declared" list)

during 0.1.4 [ticket:29]

  [ticket:27]

  expression-wise from the AST module  [ticket:26]

self.include_file(<filename>, **kwargs)

[ticket:24]

template (keyword arguments only, must be declared in that page's <%page> tag.)

propigates __nonzero__ method so it evaulates to False if not present,
True otherwise.  this way you can say % if caller:\n ${caller.body()}\n% endif

pre-process the ".." tokens before checking the filesystem

further fix to previous ast enhancement; dont log identifiers as "declared" once we're traversing inside functions since they are local to the function.

comments may contain quote characters [ticket:23]

  callable or list of callables which will be applied to the template text
  before lexing.  given the text as an argument, returns the new text.
- added mako.ext.preprocessors package, contains one preprocessor so far:
  'convert_comments', which will convert single # comments to the new ##
  format