Merge branch 'develop' into feature-icon_gravity

Conflicts:
	engine/src/control.cpp
	engine/src/graphicscontext.cpp
	engine/src/parsedef.h
Merge branch 'refactor-syntax_unicode' of https://github.com/runrev/livecode into refactor-linux_gdk
[[ IconGravity ]] Tweak to signature of drawnodata.
[[ GraphicsPerformance ]] Update OSX server to use MCGRegions
[[ ImageCenterRect ]] Implemented getter.
[[ ImageCenterRect ]] Started to integrate decompose_matrix so rotated nine-way stretch will work - not yet correct :(
[[ IconGravity ]] The iconGravity now persists.
Merge branch 'feature-icon_gravity' into develop
Merge branch 'rect_points' of https://github.com/mwieder/livecode into feature-effective_graphic_points

Conflicts:
	prebuilt
[[ EffectivePoints ]] Added release note.
Merge branch 'feature-effective_graphic_points' into develop
Merge branch 'feature/clips_to_rect' of https://github.com/montegoulding/livecode into feature-clips_to_rect

Conflicts:
	engine/src/group.cpp
	engine/src/parsedef.h
[[ ClipsToRect ]] Moved storage to bool rather than in flags (as was the last remaining flag bit).
[[ ClipsToRect ]] Added persistence for clips_to_rect.
[[ GraphicsPerformance ]] Update Win32 server to use MCGRegions
Merge remote-tracking branch 'origin/feature-clips_to_rect' into develop

Conflicts:
	engine/src/parsedef.h
[[ GraphicsPerformance ]] Update Linux server to use MCGRegions
[[ ImageCenterRect ]] Decomposition still not working.
[[ GraphicsPerformance ]] Remove sysregion.cpp from iOS project
[[ LinuxGDK ]] Fix updating of wrong variable