Touch simulation improvements

[fresswolf]

• Support for more complex multitouch gestures. One can pan like before, but then add a second finger during panning as well as transition from two fingers to one finger.
• The simulated touches can be dragged together by holding down the left shift key.
• Bugfix for the delta position of the simulated second finger (before, the delta position was the same for both fingers)
• Bugfix that caused flickering of the visualized touches
• Simulated touches now also deliver touches in the Stationary phase for more realistic simulation
• Improved the inspector view by grouping together debug settings and enabling/disabling obsolete settings during configuration
• All touches can now be visualised for debug purposes, to also visualise the touches received from a Unity remote