Flash notifications [1/2]

Trigger a camera flash for incoming notification events.

todo: add proximity and accelerometer sensors to keep it from firing
in pockets or when face down (where possible).

Note:
This commit uses a backbone of giblets from CM's torch service
on cm-11.0 (worked on by Roman Birg and Danny Baumann) to keep
the camera from causing issues.

Danny Baumann <dannybaumann@web.de>
Roman Birg <roman@cyngn.com>

Change-Id: I07a4447e37bcc4b15760fd3ad18a823c4693722d