Also change the file uploader to accept multiple file types.

- Internationalize upload errors.
- Move upload tests into their own files.
- Refactor upload dialog acceptance tests.

Authors can upload an image (or choose an existing one) from the
settings page, using the in-context uploader from PDF
textbooks. Includes tests for backwards compatibility with XML courses
-- they used a magic filename (images/course_image.jpg) which is
mapped to a location in the Mongo contentstore.

Still needs some UX work, though the backend plumbing is there.

Previously the file upload dialog was PDF- and textbook-specific. The
changes are adding parameters to the FileUpload model for the file
type, and adding an onSuccess callback to the UploadDialog view. Also
moved upload-specific SASS into its own file.

Remove js log_event (keep compatibility)

keep log_event for compatibility

Add docs for changes in #726

Fix failing grade label being editable but not saved.

Incorporate Anant's suggestions

Use calc's evaluator for staff answers in `Numercial` type

Sync up Reset Action Button Styling for Capa xmodules

address some pylint violations in the mixedmodulestore build report

Add doc strings and fix spaces

on import, when enumerating through the 'draft content', OSX environment...

Fix/cdodge/get items needs courseid

don't put the substitutions in quotes

on import, when enumerating through the 'draft content', OSX environments will have hidden binary encoded quarantine files. We don't want to try to process these as they will throw an exception when trying to be parsed. It's harmless - the import goes on fine - but it's a lot of clutter in the output logs.

small change in aggregating peer eval grades (rounds up)

Jonahstanley/help acceptance test

set first FAQ link to mktg webiste too

Persist static_tab name.