Clean addition to SwipeGesture, Rough proposal for alternate linear path motion

Hi Rikulo Team,

I've added support for two changes we needed in our application: a new SwipeGesture trigger method, and an alternate version of the LinearPathMotion which allows different easing. EDIT: The latter is being reworked, I misunderstood the MotionStart / End definitions, this can be done much more simply without so much refactoring To be reworked...