Hacking the Python, because our JS dependency management is borked.

It appears that one notification stealing focus from another causes some weirdness:
both clicking on a button on one view triggers the event on both views (the original
and the new view that stole the div). As long as the first view does *not* define
any click events, everything is fine -- this is the case for the saving notification.
I'll worry about the reason for this later; it has something to do with views
listening to models even after they no longer should be.

To create handy WarningMessage, ErrorMessage, and ConfirmationMessage classes

And delete `CMS.ServerError`

Hook up course name edit interaction, with notification framework

Not that it really matters, since the changes are invisible :)

So that modifications don't affect the model

Matching docstring in feedback.js models

removed symbolset, replaced with fontawesome throughout for new buttons; updated old code for new button at bottom of grading to also use the FA style

add MITX Feature setting to enable django admin site

Check functions need access to course-local code also, so we need to sav...

Add theming settings and simple base Sass preprocessing.

Per feedback from @cpennington. This way we'll only preprocess once,
even if the Sass compilation is invoked multiple times.

This commit adds the requisite settings and startup features to
enable integration of themes into the edX platform. It does not
yet provide hooks in any of the templates, but it does cause the
main `lms/static/sass/application.scss` file to `@import` a theme's
base Sass. Template hooks will come down the road.

CHANGELOG
---------
Define a new `MITX_FEATURE`, `USE_CUSTOM_THEME`, that when enabled,
can be used in templates to determine whether or not custom theme
templates should be used instead of the defaults.

Also define a new setting, `THEME_NAME`, which will be used to
locate theme-specific files. Establish the convention that themes
will be stored outside of the `REPO_ROOT`, inside the `ENV_ROOT`,
in a directory named `themes/`. `themes/<THEME_NAME>` will store
the files for a particular theme.

Provide a function, `enable_theme`, that modifies the template and
static asset load paths appropriately to include the theme's files.

Move the main LMS Sass file to a Mako template that conditionally
`@import`s the theme's base Sass file when a theme is enabled.

Add logic to the assets Rakefile to properly preprocess any Sass/
Mako templates before compiling them.

Reviewed by cpennington: https://rbcommons.com/s/edx/r/2/