MainActivity, assignment 2

Changed project 2, such that it runs a service in the background with
an ongoing notification which appears when service runs.

There are a few things to discuss tomorrow.
-How to avoid the listener to continue his job after the service is
shut down
-How do we display the progress of alarm logic
-Who is in charge of getting values from sensor. (alarm logic obviously)

Updated:

AbstractAntiTheftService
-Added methods resetProgressBar, incrProgressBar

AntiTheftServiceImpl
-Implemented inherited methods

MainActivity
-Manage ToggleButton and instantiate service
Merge branch 'master' of https://github.com/glukas/DistributedSystemsProjects