Added class to replace TouchEvent

Added class to replace TouchEvent

Fixes following review:

Removed Internal::TouchData::GetPoint()
Cleaned up signal sending from TouchEventProcessor
Changed new Actor::TouchSignal to pass TouchData handle as const ref.
Changed new Stage::TouchedSignal to pass TouchData handle as const ref.
Changed API of TouchData to return by value where appropriate and removed
all asserts.
Changed API of TouchData to use size_t for point index and point count.

Added test cases for touch processing using touch data ( a copy and paste
of the existing test cases, plus a negative test case for the out of bounds
check in the public API for TouchData )

Change-Id: I8a58775f7a70a3bed8514439c627f261ac4f5807