touch gestures support

pgn4web version 2.74 has been released introducing touch gestures inputs. On supported touchscreen devices the user can interact with the pgn4web chessboard using touch gestures across the chessboard.

Default pre-configured touch gestures:

• top-down swipe: load next game, cycling through
• bottom-up swipe: load previous game, cycling through
• left-right swipe: start autoplay; if autoplay already active: go to variation end or to game end
• right-left swipe: stop autoplay; if autoplay not active: go to variation start, then to parent variation, then to game start; if at last move of live broadcast: replay up to 6 previous half-moves, then autoplay forward

Try touch gestures on this live broadcast demo chessboard:
Web developers can easily customize the actions associated to each gesture.
At the moment of writing, touch gestures have been tested on iOS devices (iPhone, iPad) and on android devices (phones, tablets).