Updated jQuery and jQuery UI

Updated jQuery to 1.11.1.

Updated jQuery UI to 1.11.0 and created new theme based on existing one.
Updated Backbone and Underscore libraries

Updated Backbone.js to 1.1.2, and ensures collection.create waits for
response before updating the view.

Updated Underscore to 1.6.0, ensuring noConflict is used to avoid
conflict with babel.js.
Updated json2.js
Cleanup indentation (forgot to set noexpandtab in vim).
Merge pull request #40 from schwuk/upgrade_js_libraries

Upgrade JavaScript libraries
Allow adding comments to directories in the code browser

Fixes #39.

Due to a different table id, top comments were not shown for directories
in the code browser. Change the `selectorToInsertBefore` to support both
files and directories.

The code browser supports keyboard shortcuts for navigating directories
which conflict with the add comment dialog, so now any keypresses within
the dialog will not be propagated to avoid this. Made the dialog modal
to reflect this.

Add whitespace to selector list.