<feature>Progress Dialog for workflow execution</feature>
<feature>Progress Dialog for workflow execution</feature>

* Shows progress bar and name of executing module
* Cancel button
* Can resume
* Can cancel inside modules that report progress

gui/pipeline_view.py:
- QPipelineScene.progress: New attribute
- QPipelineScene.cancel_progress: *new
  Checks if progress bar is canceled and ask user to abort
- QPipelineScene.set_module_computing: Update/check progress bar
- QPipelineScene.set_module_progress: Check if progress bar canceled
- QPipelineView.execute: Added progress bar to execution
- ExecutionProgressDialog: *new
  Custom progress bar

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