Added frame content processing. Apparently not functioning.
Major refactoring (move callbacks into preview activity).

Thanks a lot @Sloy ! (https://github.com/Sloy)
Color format conversion to RGB added and tested (OK).
Color is picked by average value (not tested yet).
Hexadecimal color value is now printed on the screen.
Merge pull request #9 from adlebzelaznog/feature/colorDetection

Feature/color detection