Fixed a css bug in the hinter.

the bottom of the hint div, no matter what.

Still requires a little polishing, I think.

Hint submission is hidden behind a link, if there are hints to vote on.

Fixed broken tests.

Fixed some pep8 errors.

Removed the answer display next to voting.  (This was deemed distracting.)

Got rid of answer signatures - these don't work with approximate answers at all.  Instead, implemented comparison-based hint matching.

Tests are broken, hint manager is probably broken.

Fixed broken tests for hint manager.

Fixed tests to work with symbolic answer changes.

In preparation for adding hints to formula response.

Conflicts:
	common/lib/xmodule/xmodule/crowdsource_hinter.py
	common/lib/xmodule/xmodule/tests/test_crowdsource_hinter.py

No tests for this, yet.

Conflicts:
	common/lib/xmodule/xmodule/crowdsource_hinter.py
	common/templates/hinter_display.html

Jkarni/feature/chunkedupload

Signed-off-by: Julian Arni <julian@edx.org>

  Comments, httpresponse -> jsonresponse; make sure errors get relayed.

   Also adds lockfile for asynchronous status updates.

Bug fix -- subcategories in forums topic list should now be sorted alphabetically