Change the data format for gestures and make KHotkeys use EasyStroke's gesture recognition algorithm.

This allows the user to create gestures of just about any shape and should improve the detection rate significantly.
Backwards compatibility for the old gesture format is implemented. At the moment several actions can be triggered by the same gesture if they're similar enough; this probably should be fixed in the future.

We do have an explicit permission by EasyStroke author Thomas Jaeger to do this (thanks!), but we don't really need it because the license of EasyStroke allows this anyway.

FEATURE: 104763

svn path=/trunk/KDE/kdebase/workspace/; revision=939045