The convention is to use cls for first parameter in classmethods
Bugfix: Change reference to unexistent cls object

Use self instead to access the classmethod.
Black magic that fixes Evernote issue #4

If we retrieve the actual SQL query then the Paginator breaks for
querysets containing `.extra()` calls. This DIRTY HACK allows the actual
`SELECT SUM (*) FROM ...` SQL query to select and join the necessary
tables.

(I suspect that the current filtering constraints aren't fully populated
when the paginator tries to calculate the count, and this hack somehow
forces it.)

This might be a bug (or undocumented behavior) in Django's ORM querying
facility internals, so any further investigations should be done in that
direction.

Original issue is at evernote/pootle#4.
 comments for translators about working copy etc 

explanation text by dwaynebailey in irc is used
Docs: Just list required stuff in installation

There is no need to talk about Django because the procedure listed below
already installs the right Django version by using pip. Also the highlight
of the supported Django versions belongs to the release notes.
Bugfix: Specify removed field instead of relying on model

Since we removed the description_html fields in b44dcf03 (in 2.5.1 and master)
we have to specify the fields instead of relying on the model, because they
do not longer exist there.
Guard against submitter being None here as well