Move wiki decorators and exceptions into correct modules.
Fix wiki flag view to not raise NameError.
Optimized db query to only match users with email.
Minor cosmetic changes.
Added MultiQuerySet helper.
Added TransformManager for more complex queryset time annotations.
Use queryset transformation to reduce number of queries on document revision page.
Re-organized wiki/models.py.

- Moved constants into wiki/constants.py
- Moved model managers into wiki/managers.py
- Moved decorators into wiki/decorators.py
- PEP8 cleanups.
Clean pyc files at the start of foreman automatically.
bug 1034709 - restrict 'all' history view
Fixed test for previous commit.
Do more of the queryset transformation in Python than querying the database again.
Select the current_revision relation for the document get.
Merge pull request #2546 from jezdez/wiki-models-module-cleanup

Wiki app improvements including performance fixes to document revision view.