Fix order of calls when creating ScreenManager
Fix order of calls when creating ScreenManager

If the ScreenManager's "on_current" is called before self.transition is set, it will crash because on_current tries self.transition.stop(). This fixes the issue by forcing the transition to be set by the time event bindings are done.
jegger/kivy,kivy/kivy,LogicalDash/kivy,KeyWeeUsr/kivy,kivy/kivy,jegger/kivy,rnixx/kivy,KeyWeeUsr/kivy,matham/kivy,Cheaterman/kivy,Cheaterman/kivy,Cheaterman/kivy,LogicalDash/kivy,KeyWeeUsr/kivy,akshayaurora/kivy,jegger/kivy,rnixx/kivy,LogicalDash/kivy,rnixx/kivy,Cheaterman/kivy,bionoid/kivy,inclement/kivy,LogicalDash/kivy,kivy/kivy,inclement/kivy,matham/kivy,KeyWeeUsr/kivy,bionoid/kivy,matham/kivy,akshayaurora/kivy,matham/kivy,bionoid/kivy,bionoid/kivy,inclement/kivy,jegger/kivy,akshayaurora/kivy