Added encrypted and plaintext backup / restore. Re-added import SMS database. Removed apk expire. Added the choice between passphrase protection and the Android screenlock. Added more conversation colors and themes. Added a choice for the backup location.
warning: this version crashes at startup in Android 4.4, see https://community.signalusers.org/t/beta-feedback-for-the-upcoming-android-4-43-release/8242