GafferImageUI : Set ImageViewUI top/bottom toolbar minimum heights
GafferImageUI : Set ImageViewUI top/bottom toolbar minimum heights

A workaround to avoid jumps as widgets show/hide.

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