Minor cleanups on views, templates and url patterns
Improve Django 1.5 support: Djblets imports cleanups

Avoid using deprecated code to allow using latest Django releases
Cleanup: unified admin URLs
Unified names for named URL patterns
Cleanup: removed dead code

This code path was never reached.
Rename URL pattern to align with Evernote
Reposition URL pattern to align with Evernote

This eases picking their changes
Wrap URL pattern

This eases picking Evernote changes
Cleanup: unified and cleaned URLs
Fixed URL pattern name
Name URL patterns
Use url template tag
Cleanups: Use URL names and url template tag
Cleanup: coding style fixes
Cleanups: Renamed vars and other minor changes to align with Evernote

This eases picking the next commits.
Cleanup: gathered templates in a single location
Cleanup: Fix template references in templates that we have and Evernote doesn't
Cleanup: Move remaining templates to pootle/templates/

Also moved templates from pootle/templates/common/ to pootle/templates/core/

This gets Pootle working again since the app templates loader was removed in
the previous commit.
Improved JavaScript handling of the captcha

Less hackish, less requests, less duplicated code, cleaner separation of
code and not tightly coupled to the editor.

JavaScript code that makes XHR POST requests will need to pass two special
parameters (`sfn` and `efn`) which are the success and error callback
function names which will be executed once the captcha has been
successfully resolved.

Note that the captcha can now be identified via the HTTP 402 status code
(Payment Required) — the captcha can be considered like a sort of payment
the user needs to make in order to continue further. YouTube also makes
use of the HTTP 402 status code for this purpose.
Moved captcha form into its own module

This will allow us further reuse of the form and its functionality in
other parts of the codebase.