Fix crash on mouse move over an about-to-become-visible GLWidget.
Fix crash on mouse move over an about-to-become-visible GLWidget.

We need to call the init method after a GL context has been created, but before any events requiring GL have been triggered. We had been doing this from GLWidget.__draw(), but it was still possible to trigger mouseMove events prior to drawing by hovering over top of an about-to-become-visible GLWidget. resizeEvent seems to always be triggered prior to both draw and mouseMove, ensuring GL is initialized in time for those other events. Calling it here does mean we call init() more than needed, but it's safe.

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