More cleanups
Do not display any precontent block (this was removed in custom templates)
Partial pick: Updated the entire base.html template from the override one

Pick notes: Some of the changes are not interesting for us. Other changes
were undone in:

- evernote/pootle@373fbfb9
- evernote/pootle@933b03f1
- evernote/pootle@6bb67a86

and to avoid picking extra commits we just pick here the commits that are
not undone and that are insteresting for us.

Conflicts:
	pootle/templates/layout.html
Under Windows, locale names are different and setlocale() with regular locale names will fail; so just set the default locale and quit early. This will avoid polluting the logs with numerous 'Failed to set locale' debug messages

Conflicts:
	pootle/middleware/setlocale.py
Cleaner and flattier buttton shadows
Removed extra charset declaration
Fix number formatting crash under Windows
Moved the 'Latest news' widget/rss to Admin section

Conflicts:
	pootle/templates/admin/dashboard.html
	pootle/templates/home/home.html
Cleanup: coding style fix
Reuse existing code

Picking this required extensive changes due to the huge differences between
Evernote code and our code in this specific view.

Conflicts:
	pootle/apps/pootle_translationproject/views.py
Ignore empty path parts
Revert to previous behaviour
Show translations coming from update_stores

Conflicts:
	pootle/apps/pootle_store/models.py
Added creation_time field to Unit

Pick notes:

- Changed name of the migration to keep the numbering.
- Created the migration again, since we did additional changes to the model.
Check for permissions by using the decorator
Point to the editor URL

Conflicts:
	pootle/apps/pootle_statistics/models.py
Unified units query

Conflicts:
	pootle/apps/pootle_store/models.py
Singularize permission checking

Views only check a single permission at a time.

Conflicts:
	pootle/core/decorators.py
Cleanup: removed deprecated fields and code

Pick notes: The migration was recreated and renamed.

Conflicts:
	pootle/apps/pootle_store/models.py
Followup for .pending and .tm removal

There was some references to the code dropped in the previous commit, so we
removed them. But since they were on the upgrade code, removing part of that
code rendered it useless, so we dropped the upgrade path for the ancient
Pootle versions (2.1.0 and older).

So to avoid surprises we added a check in the setup command to warn people
that they are trying to upgrade from a really old version and ask them to
do an intermediate upgrade.

Added a note about this on the upgrade instructions and included references
in the release notes as well.