changed repo references to mrg's github
Merge branch 'MobRulesGames/master' into linux

Conflicts:
	ai/ai.go
	ai/ai_test.go
	gin/input_test.go
	gos/cgo_darwin.go
	gos/cgo_linux.go
	gos/cgo_windows.go
	gui/check_box.go
	gui/combo.go
	gui/file_chooser.go
	gui/gui.go
	gui/scroll.go
	gui/text.go
	gui/text_edit_line.go
	gui/text_line.go
	gui/widgets.go
	sprite/shared_sprite.go
	sprite/sheet.go
	sprite/sprite.go
	sprite/sprite_test.go
	system/system.go
	util/algorithm/generic_test.go
	util/algorithm/graph_test.go