Update Changes.md
Update Changes.md

Copying the fixes from 0.55_maintenance into the release notes for the next 0.56 release.

andrewkaufman/gaffer,lucienfostier/gaffer,hradec/gaffer,ImageEngine/gaffer,lucienfostier/gaffer,ImageEngine/gaffer,hradec/gaffer,GafferHQ/gaffer,andrewkaufman/gaffer,GafferHQ/gaffer,boberfly/gaffer,johnhaddon/gaffer,GafferHQ/gaffer,johnhaddon/gaffer,andrewkaufman/gaffer,lucienfostier/gaffer,johnhaddon/gaffer,boberfly/gaffer,boberfly/gaffer,lucienfostier/gaffer,andrewkaufman/gaffer,ImageEngine/gaffer,johnhaddon/gaffer,GafferHQ/gaffer,andrewkaufman/gaffer,hradec/gaffer,hradec/gaffer,hradec/gaffer,boberfly/gaffer,ImageEngine/gaffer,johnhaddon/gaffer,GafferHQ/gaffer