fmbtgti: wait* function documentation made more exact
fmbttizen: distance scaling in pinch* methods made easier to understand

pinchOpen and pinchClose defaults changed: now the gesture ends to
(pinchOpen) or starts from (pinchClose) from half of the distance
between the gesture central point and the edge of the screen (in
finger's movement direction). Screen edge is always reached if
distance is set to 0.5.