gpu: set editText for color control read-only

To not confuse user that this field actually could
change anything, set it to read-only.

Signed-off-by: Blechd0se <alex.christ@hotmail.de>
aero: add material design style

 * Just a couple of small layout adjustments to fit the
   material design

 * Added back some missing summary texts

Signed-off-by: Blechd0se <alex.christ@hotmail.de>
testsuite: fix a potential crash

Signed-off-by: Blechd0se <alex.christ@hotmail.de>
Version 2.1.0 Beta 1

Starting with beta releases now!

Signed-off-by: Blechd0se <alex.christ@hotmail.de>