Feature/cdodge/subsection edit page

Merge branch 'feature/cale/cms-master' of github.com:MITx/mitx into feature/cdodge/subsection-edit-page

Conflicts:
	cms/djangoapps/contentstore/views.py
	cms/templates/widgets/units.html

update creating a new unit to use an empty template. Also twiddle the units.html and base.js where we put the unit Location on the <li> element

Wire up the unit location display

added course page with log in and sign up

Merge branch 'feature/cale/cms-master' of github.com:MITx/mitx into feature/cdodge/subsection-edit-page

Conflicts:
	cms/static/js/base.js

Feature/tomg/cms library

add a 'safety switch' where we add new content into GridFS with a filena...

Feature/cale/cas component delete

Hook up the component delete button to the backend. Don't break if the process of updating a parent unit after deleting is interrupted (leaving a pointer to a missing module)

Enable reordering on the unit page

Feature/cdodge/subsection edit page

add subsection edit page to the project with a shared 'unit' widget that will render out unit lists. Both edit_subsection and overview.html will share this widget

add subsection edit page to the project with a shared 'unit' widget that will render out unit lists. Both edit_subsection and overview.html will share this widget

Merge branch 'feature/cale/cms-master' of github.com:MITx/mitx into feature/cdodge/subsection-edit-page

add a 'safety switch' where we add new content into GridFS with a filename (which GridFS maintains an index on) in case any assumptions about our new id scheme proves to be false. We can query by filename (which is a /tag/org/course/category/name format) so it'll be unique