StandardStyle : Fix arrowheads on axis-aligned auxiliary connections
StandardStyle : Fix arrowheads on axis-aligned auxiliary connections

Fixes #2647.

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