input: re-organize touch input handling to make it more generic and move it into its own lib
touch: add touch gesture detectors for pinch/zoom, rotate and swipe
touch: make the touchscreen's DPI available to gesture detectors
CSlideShowPicture: add m_bCanMoveVertically
slideshow: use swipe left/right gestures instead of manual swipe detection based on pan gesture
[ios] - add unified gesture handler to ios xcode project
[ios] - use generic touch handler
[touch] - add a mapping for 2 finger swipeleft (Back) as it was before on ios because of lack of hw back button
[ios] - implement swipe support