allowing usage of custom TouchProcessors (closes #271)

    Users can create custom TouchProcessors to have more control over touch event
    handling. This allows applications the opportunity to perform custom handling
    of touch input before TouchEvents are dispatched, or prevent the TouchEvents
    from being dispatched at all.
fixed rounding error in render textures
moved TouchProcessor and TouchMarker into 'starling.event' package

Since TouchProcessor is now designed to be extended, it shouldn't be hidden in the 'core' package.
now immediately dispatching a HOVER touch event after a native MOUSE_UP (closes #146)
fixed refactoring error in previous commit

That error caused touches to be lost sometimes in multitouch situations.
more TouchProcessor refactoring

I made many of the properties of the "Touch" object writeable; this is required for TouchProcessor subclasses to create / modify their own touch objects. Furthermore, I removed the "updated" property of Touches and instead pass only the updated touches to the "processTouches" method.

The reasons for these changes can be found here:
https://github.com/PrimaryFeather/Starling-Framework/commit/a83d3537eff90b13bd9936bb4ab48d8b61cb8779
updated project properties
made bitmap font registration case INsensitive (helps with upcoming commit)
now using texture name for bitmap font registration in AssetManager (closes #378)
raised version to 1.4
updated KeyboardEvent documentation (since those events are now broadcast)
updated CHANGELOG for v1.4
Merge branch 'master' into vertexdata-bytearray