Handle GroundOverlay for KML, first pass
Handle GroundOverlay rotation

by adding a L.RotatedImageOverlay method inspired by @bbecquet code, thx to him :)
todo, fix rotation loss during zoom anim
Handle GroundOverlay rotation during zoom anim

(not sure it's the best way, but it works)
add getBounds() method to L.RotatedImageOverlay in order to allow fitBounds() on KML layer
Merge pull request #133 from shramov/kml_groundoverlay

Handle GroundOverlay for KML