<bugfix>Fix issue with deleting modules and connections</bugfix>
<bugfix>Fix issue with deleting modules and connections</bugfix>

There was a major bug where state was not being updated when deleting
modules and connections.  Specifically, removeItems was being called
instead of remove_module/remove_connection.

gui/pipeline_view.py:
  - QPipelineScene.setupScene: call remove_module instead of removeItem
  - QPipelineScene.delete_selected_items: use remove_module/
    remove_connection calls, also refactor some code to streamline

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