Cleanup log tags (close #117)

Signed-off-by: Daniele Ricci <daniele.athome@gmail.com>
Moving Google Play stuff to dedicated flavor

Signed-off-by: Daniele Ricci <daniele.athome@gmail.com>
Depend on Google Play Services only in googleplay flavor

Signed-off-by: Daniele Ricci <daniele.athome@gmail.com>
Creating modular push client service (DOES NOT BUILD)

Signed-off-by: Daniele Ricci <daniele.athome@gmail.com>
Google Cloud Messaging classes gone in their own flavor

Signed-off-by: Daniele Ricci <daniele.athome@gmail.com>
Abstract billing interface (UNTESTED)

Signed-off-by: Daniele Ricci <daniele.athome@gmail.com>
Merge branch 'master' into audio_message

Signed-off-by: Daniele Ricci <daniele.athome@gmail.com>

Conflicts:
	app/build.gradle
	app/src/main/AndroidManifest.xml
	app/src/main/java/org/kontalk/ui/ComposeMessageFragment.java