1st step to clean player.cpp and player.h
Finished step 1
start to implement custom controller
Added some more buttons on the controller
Simplified MCPlatformPlayer (step 3)
reverted some changes so as not to view the movie controller
Fixed dragging of the thumb. TODO: Remove commented out code
Implemented fastforward/fastback. Needs a bit refinement
Replaced playfastforward() and playfastback() with playfast(Boolean forward)
1st attempt to implement selection handles and interaction
Implemented keyboard input for play/pause/stepforward/stepback
Implemented popup of volume slider
Fixed memory leak, ScrubForward/Back, drag-click on the thumb
Custom controller works, but does not look nice
Merge remote-tracking branch 'upstream/develop' into feature-multimedia_mac

Conflicts:
	engine/src/player.cpp
Made the custom controller to look pretty
Added:
1) clicking-anywhere causes the volume pop-up window to close (if open)
2) volume-slider that is highlighted up to the selected volume
3) highlighting the "already-played" area of the well
Made rounded rectangles for well and thumb
Some more design improvements
More design improvements 2