<ticket>#472</ticket>
<ticket>#472</ticket>

Also fixed a problem where you couldn't change parameters that popup another
widget in mashup preview because they were triggering a change_view event.

--

gui/vistrails_window.py
   QVistrailsWindow.applicationFocusChanged()
     if the current widget that has the focus is a child of a ConstantWidgetMixin
     or a QParamExploreView, we won't generate a change_view event.
     Also added a comment explaining that.

VisTrails/VisTrails,VisTrails/VisTrails,hjanime/VisTrails,Nikea/VisTrails,celiafish/VisTrails,minesense/VisTrails,hjanime/VisTrails,minesense/VisTrails,hjanime/VisTrails,Nikea/VisTrails,minesense/VisTrails,minesense/VisTrails,celiafish/VisTrails,hjanime/VisTrails,VisTrails/VisTrails,celiafish/VisTrails,VisTrails/VisTrails,Nikea/VisTrails,Nikea/VisTrails,VisTrails/VisTrails,celiafish/VisTrails,minesense/VisTrails,hjanime/VisTrails