CSS button group fix
Added students hover tip for training requirements
Fixed query hover bug (removed cached of popover)
Change hover/explain show attribute from show='position' to just position for cleaner syntax, less bulk.  Also, added child selector triggering to [explain] popover to fix issue with some popups blocking the field label.
Added more user messages back into ftss-user-messages.js
Removed track by for all hg-repeats due to bug causing data to not update after edits
Added .modal-dialog to all ng-dirty CSS rules (to stop highlighting search fields)
Changed Unit to FTD for menus/dropdowns to be less confusing to UTMs/MTFs
More CSS reorganization, cleanup, fixed some issues with Request page styles style priority
Minor selectize config cleanup
Major rewrite of FTSS.filters

- Rewrote all custom filtering code due to issues with custom tags not
removing properly across pages

- Significantly shortened page links on custom tags by using shorthand
lookups instead of full queries

- Fixed bug in TODAY filter creator & changed to Angular date filter
function for reliability

- Pre-cached all routes and filters at the beginning of app
initialization to reduce overhead of page changing

- Fixed issue with multiple custom filters not joining properly when
combined with timeout filter (for cached partial results)
Removed secondary search boxes & added more CSS3 animation