Add icons and flash status
Integrate Nova SDK

Attempt to fire flash using the current settings any time the
capture button is tapped.

Maintain an abstraction layer in front of NVFlashSettings as
SSNovaFlashSettings is a closer match to our UI and handles
translation of brightness/color temp to warm/cool values.
Setup and enable flash immediately

Testing flash unit; in the future we should enable flash only when the
capture screen is active and when the flash is turned on.
Enable testing of flash from flash settings
Update flash status icon to match device status
Enable and disable flash unit when appropriate