Added "getting started" section to readme.
Moved some constants to the top of the class def.
Added break statements to fix fall-through problem on gesture detection.

Gesture detection for strokes used a switch statement with no breaks
(oops) so the switch always fell through to the last case statement. The
first case statement detected thin strokes so it was impossible to
generate a thin stroke since the code would always fall through to the
last statement (squiggly stroke).
Increased the tolerance of minor squigglies in non-squiggly stroke gestures.
Added basic action component.
Added basic action component