Settings: statusbar clock customization + initial interface + color picker

- added slims clock and date customizations for status bar
- added our own modded marginov color picker which we use as default
- added initial interface settings. A bit empty currently but we are on
  alpha and it will be filled fast for sure. Added as well two empty
classes
  due that we need them later

Originally by kufikugel. I just ported to 5.0

Change-Id: Ife03bc55705e9576edcca030185bdd2349e9e270