Merge branch 'add_redscreen' into 'master'

Add app RedScreen

Trivial: just show the red screen. But it can be useful.

Also makes nice demo of some Android features.

See merge request !1024

metadata/org.vi_server.red_screen.txt

@@ -0,0 +1,18 @@
+Categories:None
+License:MIT
+Source Code:https://github.com/vi/redscreen.apk
+Issue Tracker:https://github.com/vi/redscreen.apk/issues
+
+Summary:Show red screen
+Description:
+Shows bright red screen - for use as an ad-hoc emergency light or a penalty card. If triggered from outside, it turns on the screen and raises atop of the lock screen. The colour can be overridden with an intent parameter (see README on Github).
+.
+
+Repo Type:git
+Repo:https://github.com/vi/redscreen.apk
+
+Build:1.1,1
+    commit=6df004efa9c5b2556ee8f84c2ff5526f3a3f6b07
+
+Auto Update Mode:None
+Update Check Mode:Tags