The problem was we were pulsing the display power briefly down while
reentering the ON state (because the ON states exit rule turned it off).
Instead we now just turn off the screen on entry to DARK or LS states
* Have state machine properly enter deep sleep based on loss of mesh and phone comms.
* Default to enter deep sleep if no LORA received for two hours (indicates user has probably left the mesh).
Signed-off-by: Kevin Hester <kevinh@geeksville.com>
