The introduction of the proprietary PhotoEditor SDK prevented this app from
being truly free and open source, and so F-Droid could no longer build the app.
By adding a licensing flavor dimension, we segregate the non-FOSS code to a
separate version, while providing a FOSS version without the editor.
To build the proprietary version, select one of the proprietary build variants
from Build Variants pane in Android Studio (on the left side of the window).
Fixes#1706.
