various fixes for desktop notifications  - removed notifications for passing periods  - added notifications for period start (was previously only end)  - added safety checks for browsers that don't support notifications api  - removed debug code
various fixes for desktop notifications
 - removed notifications for passing periods
 - added notifications for period start (was previously only end)
 - added safety checks for browsers that don't support notifications api
 - removed debug code

HarkerDev/bellschedule,HarkerDev/bellschedule