Fixed provider's exported attributed with Android 4.4

The default value of the exported attributed from Provider changed
with Android 4.3 from true to false and since we are now targeting
Android 4.4 (SDK level 19) all providers became unexported. The fix is
simply to explicity set the exported attribute to true.
main: Correct text for start/stop button

MainActivity's start/stop button showed 'start' as text even if the
service was running. Make sure that the button is prepared with the
correct text once the Activity is created.
MAXS Pre-Release 0.0.1.7