Move targetSdkVersion back down to 19.

// FREEBIE
Update gradle-witness and actually use spongycastle.

// FREEBIE
proguard has guarded its last pro

// FREEBIE
make the light theme light

Fixes #2111
Tested on GB and LP
// FREEBIE
Update language translations.

// FREEBIE
Fix escaping in danish translation.

// FREEBIE
Add jobs for pending push messages during migration.

// FREEBIE
Bump version to 2.3.0

// FREEBIE
Update to latest zxing QR code scanner.

Closes #2078

// FREEBIE
Make GCM re-registration failure notification based.

// FREEBIE
rollback to appcompat v20

v21 appears to just not be ready for production given the bugs.
// FREEBIE
Don't completely disable GCM.

// FREEBIE
Updated translations.

// FREEBIE
Bump version to 2.3.1

// FREEBIE
The future is the other direction.

// FREEBIE
Add callback method parameter to axolotl decrypt functions.

// FREEBIE
Guard against fragment disappearing before callback.

// FREEBIE
Do thread trimming as JobManager job rather than AsyncTask.

// FREEBIE
reorder window feature requests in MediaPreviewActivity

ActionBar is initialized in a different way by AppCompat v20 compared to
ABS or v21 even...
// FREEBIE
fix for ringtone selection with android-support-v4-preferencefragment