Add auto recording feature

- Add end time field in talk editor

- Add auto record button in record interface

- Add dialog box if no talk available for auto recording

- Add dialog box if no room selected for auto recording

- Add auto record widget to set up full screen countdown and talk info
display

- Add flash screen at 1 minute and at 30 seconds mark

- Add alert sound at 2 second mark before start of recording

- Add code for start/stop recording for each talk that is eligible
for auto recording

Author:    Laura Chen <laura.di.chen@gmail.com>