Merge branch 'feature/cale/cms-master' of github.com:MITx/mitx into feature/ichuang/cms-input-filter-latex2edx

remove the — from the HTML, this apparently is causing the CAS and...

remove the — from the HTML, this apparently is causing the CAS and LMS to barf on staging, but strangly not on dev

remove HTML comment from schematiceditor template

Merge branch 'feature/cale/cms-master' of github.com:MITx/mitx into feature/ichuang/cms-input-filter-latex2edx

fix exception in LMS when rendering newly create multiple choice problem...

fix exception in LMS when rendering newly create multiple choice problems. The capa module is barfing on the HTML comment which was in there and the XML parser couldn't handle it.

Fix/cdodge/cas bugs

Conflicts:
	cms/templates/widgets/header.html

Fix/cale/edge bugs

Conflicts:
	cms/static/js/base.js

save_item should also do proper 'is this element draft aware' logic so that incorrect versioning occurs on elements which do not support versioning at this point in time (aka courses, sections, and subsections).

Feature/cdodge/cas new course

swallow exceptions when generating thumbnails

Merge branch 'feature/cale/cms-master' of github.com:MITx/mitx into fix/cdodge/cas-thumbnail-exception-handling