Mindtagger cursor movement with keyboard up/down
Migrated keyboard events to cfp.hotkeys

https://github.com/chieffancypants/angular-hotkeys
Left/right keys for mindtagger-selectable-words
Added a demux to route keyboard events of directives to the item under cursor
Cleaned up MindtaggerTaskHotkeysDemuxCtrl
Made possible to shrink selection of mindtaggerSelectableWords