Added angularjs service that sets a flag in the root scope as true, and after 5 seconds sets it as false.

This is used to temporarily show alerts in the application when certain conditions (errorr, mostly) happen.
Rails and Devise alerts are shown for 5 seconds using the timerFlagSvc angularjs service.
Reorganization of code in the FeedbunchCtrl angularjs controller.
WIP: use angularjs services to set/unset several values in the root scope (currently selected feed or folder, currently open folder, currently open entry).