option: shut down GPS when in standby for X minutes

[Martin Kolman]

• this feature should be optional

• if modRana is in standby for more than X minutes (5 as default ?), it will shut down GPS and pause any other potentially battery draining activity, that was not explicitly requested by the user
  • so this means it won't for example shut down batch tile download or turn-by-turnn-routing
  • wkake-locks ? :P
  • once standby is over, it will restore everything back to the "normal" state

• standby:
  • application window is not active
  • alternatively -> screen turned off & turn by turn navigation not running
  • how modRana understands standby should be configurable