Merge branch 'ring' into 'master'

Add ring app

Requires following packages to be installed on the buildserver (perhaps more, these two were required for me):

* `autopoint`

* `swig`

See merge request !1165

metadata/cx.ring.txt

@@ -0,0 +1,28 @@
+Categories:Phone & SMS,Internet
+License:GPLv3+
+Web Site:https://ring.cx/
+Source Code:
+Issue Tracker:https://tuleap.ring.cx/projects/ring/
+
+Name:Ring
+Summary:Secure and distributed communication platform
+Description:
+Ring (formerly SFLphone) is a free distributed multimedia communication
+software. It is developed by Savoir-faire Linux with the help of a global
+community of users and contributors. Savoir-faire Linux is a Canadian company
+specialized in Linux and free software.
+.
+
+Repo Type:git
+Repo:https://gerrit-ring.savoirfairelinux.com/ring-client-android
+
+Build:2.0.003,20
+    commit=0011b9ba52b6ac3aab97a2bf42a608f83f0ec15c
+    output=ring-android/app/build/outputs/apk/app-release-unsigned.apk
+    build=echo -e '#!/bin/sh\ngradle "$@"' > gradlew && \
+        export ANDROID_NDK_ROOT=$ANDROID_NDK && \
+        export ANDROID_ABI="armeabi-v7a" && \
+        ./compile.sh release
+
+Auto Update Mode:None
+Update Check Mode:None