NbtkWidget: white spaces fixes in function parameters
NbtkWidget: white spaces fixes in function parameters

clutter-project/mx,jonnylamb/mx,jonnylamb/mx,jonnylamb/mx,clutter-project/mx,pwithnall/mx,clutter-project/mx,pwithnall/mx,pwithnall/mx,jonnylamb/mx,clutter-project/mx,pwithnall/mx