Fix tree algorithm edge case

Recursion is hard apparently, derp.
Cap description size on tree nodes

Also change description to shortname in bar chart.
Remove barchart from course view
Intermediate checkin for course view tree
Remove call to removed function
Refactoring d3 logic for clarity

The d3 tree building logic is still pretty messy and it's critical
that it is cleaned up if we are to make any extensions/modifications
to it. Still more cleanups to come.
More refactoring of d3 logic
D3 refactoring continued
Use guids for node ids

Also avoid modifying the original concept tree with scores,
instead make a copy of it each time we need to use it.
Some more refactoring for clarity
Merge branch 'develop' into course-tree

Also a few refactorings

Conflicts:
	js/views/courseview.js
	js/views/studentview.js
Intermediate commit of course view tree

Need to fix issue with binding click event on nodes to the wrong
data set.
Fix callback for coureseview tree
Remove use of deprecated 'name' column in Student