Add setting to set the virtual host of a Celery broker
Add some documentation around XModule/XModuleDescriptor initialization.
studio - sets initial studio nav revisions (WIP)
studio - proofs nav's flex grid widths/alignment
studio - revises button styling/states for primary nav
studio - revises studio nav visually and adds help links
studio - revises main nav dropdown jquery selectors
studio - abstracts and animates main nav dropdown icons
studio - makes course org/number visually inline in main nav
studio - removing reference to old edX Studio logo on index view
studio - removing unused/needed studio logos
studio - replaces flex-grid based widths with % for main nav
studio - wraps nav elements in floated containers for easier layout
studio - syncs up  Sass variable with edX's official blue
Working prototype of crowdsourced hinting module.

Conflicts:
	common/static/coffee/src/logger.coffee
Began work on instructor view to hinting system.
Added moderation feature - you can now choose to hold all hints for moderator approval before showing.
Finished prototype of hint moderation view.  Began re-writing tests of the crowdsource hinter module.  (Old tests no longer cover all the code, now that moderation has been added.)
Made tests of the crowdsource hinter module more standardized and easier to read.  Fixed database non-initialization bug in crowdsource hinter module.
Fixed epic git rebase meltdown.  No new features.
Made correct/incorrect determination in coffeescript a little more sensitive.  Still very hacky.