refactoring and new accessor
debug log
let  rescaleCache handle the float values
this fixes the viewPort for float zoom values. See comments in code
make sure we use the correct scale at the end of the gesture. Also call onAnimationEnd so that everything is handled by the controller
prevent unwanted scroll during animation. Especially will be used at the end of a scale gesture.
Sometimes there are unwanted scroll just at the end. This will prevent it
introduction of nineoldandroids
some refactoring and fixes to better handle scale gesture