[[ ImageRepUpdate ]] Refactor MCImageBitmap -> MCGRaster conversion
[[ ImageRepUpdate ]] Replace MCImageBitmap with MCGImageRef in frames locked from MCImageReps
[[ ImageRepUpdate ]] Split unpremultiplied bitmap locking to separate methods
[[ ImageRepUpdate ]] Replace MCImageBitmap in MCImageDescriptor struct with MCGImageRef
[[ HiResPatterns ]] Implement resolution independence for pattern images
[[ HiResPatterns ]] Prevent skia assertion failure when drawing hi-res patterns
[[ ImageRepUpdate ]] Fix frame density & duration not being set
[[ HiResPatterns ]] Fix OSX compile after refactor
[[ HiResPatterns ]] Fix linux compile errors after refactor
[[ HiResPatterns ]] Update thirdparty submodule.
[[ HiResPatterns ]] Store image filter in pattern refs
[[ HiResPatterns ]] Add image filter param to OSX theme background pattern
[[ HiResPatterns ]] Add feature release note.
Merge branch 'refactor-imagerep_update' of https://github.com/runrevian/livecode into refactor-imagerep_update

Conflicts:
	engine/src/idraw.cpp