input: re-organize touch input handling to make it more generic and move it into its own lib
input: implement touch input through mappable actions
touch: add touch gesture detectors for pinch/zoom, rotate and swipe
touch: make the touchscreen's DPI available to gesture detectors
slideshow: use swipe left/right gestures instead of manual swipe detection based on pan gesture
fix generic touch action handler
fix multi touch tap/hold recognition in generic touch input handler
fix mapping