Added more threading checks to EventLoop.py.
Added more threading checks to EventLoop.py.

QTimers are meant to be used on a single thread, and start() should be called on the timer's thread and no other. This means the idle methods, signals and callbacks should only be used on the UI thread.

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