TouchEvent class represents a platform independent touch event.
This gets created from a platform specific touch event.

Its used to contruct/detect a gesture.
Reference Used: http://flohofwoe.blogspot.com/2014/10/cross-platform-multitouch-input.html
TouchEventMgr is responsible to process the TouchEvents.
Stores a collection of gesture detectors, which store the current state of a gesture!
A simple gesture detector (for example for the input touch mechanism being build for tangram).
Has method to detect a tap gesture based on touchEvents recorded from a platform!

Also owns the state of the tap gesture: m_tapped and tap position.
Tap gesture will be reset at the end of an update call by calling the reset method.
Enum to represent different state of a generic gesture. Will be helpful in complex gestures like pinch and pan.
empty classes for pan and pinch gestures!
TODO: Implement these gestures.

Used in TouchEventMgr with other gestures like TapDetector.