More consistent way of determining logged user in linux.
Handle HiDPI screens in Linux alert (new SystemFlash).
Fixes to alerts in non HiDPI Linux systems.
Final fixes to Linux alert spacing and heights.
Replaced Windows Lock with stronger C-based version, refactored and simplified module structure.
Fixed lock.kill() call.
Lock: Ensure valid password length.
Lock: Don't expect a callback on stop(), cause we ain't getting one.
Handle no logged user when firing lock.
Lock: clearTimeout when stopping if timer 'no logged user' exists.
Fixed prey-lock shebangs to avoid bashisms.