* Add decoding for some encoded messages parts, i.e.
  attachments' name, message header, etc.
* Remove overriding for MessageAttachment's __getitem__
  method, so we can call the members directly in django
  templates.

Signed-off-by: Anders.Du <ander.dy@gmail.com>
Fix the IndentationError in last commit.
Support for Django 1.4 with python 2.5, copied from
https://github.com/jhmaddox/django-precompressed/issues/1
("AttributeError: StringIO instance has no attribute 'name'")
Applied cleaned up fixes from Anders.Du (duyu)
Added subject decode
Merging in changes from buriy:master (pr #5)
Minor PR cleanup and reorganization.
Adding missing import.