fix Play Store feature filtering
fix Play Store feature filtering
Merge pull request #1173 from cascheberg/fix

@cascheberg fix Play Store feature filtering: telephony not required
Added build flavour support to different app stores (google play, github and fdroid now supported)
Fix for #1016: Added support to rewrite the Android versionName and versionCode on the fly without touching the original AndroidManifest.xml so that we're not changing it every version bump.
Swapped out the github mozilla-services Ivy repository in preference for jcenter to satisfy f-droid requirements.