Change drag/multi:drag ui events to bubblable
Add `DisplayObject#globalToLocal` and `DisplayObject#localToGlobal`

Fixes #169
Merge pull request #193 from uxebu/points-globallocal

Add `DisplayObject#globalToLocal` and `DisplayObject#localToGlobal`
Add to change log
Implemented rudimentary charCode to be returned by keydown event.
Group globalToLocal/localToGlobal tests together
Add tests with readable values and fix implementations and other tests
Remove a memory leak where saved touch data would never be released
Remove dead code branches for touch events
Bring touch events back into the main switch block
Reset properties to null instead of deleting them
Emit drags only for real drags (mouse is down)
Emit deltaX/Y and diffX/Y values for mousemove events, too
Add deltaX/Y to touch events as well (pointermove/drag)
remove console.logs
Add to changelog
Add experimental `elementsUnderPointer` renderer option
Add private/internal module to wrap svg intersection checks
Prevent unnecessary object creation
Extend property matchers so that they can also check property values