add pinch, spread, rotate and inward/outward pan gestures
use new directions in pan/swipe gesture
fix direction rectification of pinch/spread gestures
use pinch/spread gestures to set zoom mode
fix DEBUG location in case ges_ev is nil
use rotate gesture to set screen mode
Merge pull request #21 from chrox/more_gestures

add pinch, spread, rotate and inward/outward pan gestures