* renamed the 'icon-star' style to 'icon-vector-star' to keep backwards compatibility for icon-* classes
* changed relevant styles in zephyr.css; added FontAwesome assets
* changed relevant CSS classes in base.html, left-sidebar.html, ui.js, message.handlebars
* added new fonts.css to start consolidating all font-based assets
* added fonts.css to PIPELINE_CSS in settings.py under 'portico' and 'app'
* modified the stars test suite to reflect new star icon class name.
(imported from commit 3116fcfd4b5fb4edecd457da554fea616bb7081b)
Allen Rabinovich