Make user profiles work again after the switch to an XMLModuleStore. Staff user histograms are still broken

Begin using a Keystore for XML parsing. Still broken: sequence icons, custom tags, problems, video js

Move the resources_fs abstraction into the primary DescriptorSystem, as it is needed for more than just XMLParsing

Revert "Make import work via mako again, to unblock others while I work on making the LMS work using XModuleDescriptors"

This reverts commit 6fdf44fe.

Conflicts:
	cms/envs/common.py

Queue up MathML conversion to be after render

Put in a fix for the Profile page (a bug was showing up for new users). A basecamp discussion will be started on the issue.

From https://www.pivotaltracker.com/story/show/31700967
Fixes #137

Kf html edit

Make import work via mako again, to unblock others while I work on making the LMS work using XModuleDescriptors

Added new styles for the sequence nav including completeness

Added fix for the sidebar buttons in the courseware

Remove semantically meaningless sections from course.xml by moving their attributes onto the contained element. If there is more than one contained element, turn the section into a sequence. Also handles includes