This is my attempt to tame the current signal mess on VisTrails.

--------------------------------------------------------------------------------

vistrailChanged is emitted by QViewManager.vistrailChanged
		   	      QViewManager.closeVistrail
		   	      VistrailController.invalidate_version_tree
                              QVersionTab.vistrailChanged

QVersionTab::vistrailChanged is caught by QViewManager.vistrailChanged

VistrailController::vistrailChanged is caught by QVersionTab.vistrailChanged

VistrailController::vistrailChanged is caught by QQueryTab.vistrailChanged

QViewManager::vistrailChanged is caught by QBuilderWindow.vistrailChanged

invalidate_version_tree 

--------------------------------------------------------------------------------

stateChanged is emitted by VistrailController.setChanged
	     		   VistrailController.setFileName

VistrailController::stateChanged is caught by QVistrailView.stateChanged

--------------------------------------------------------------------------------

versionSelectionChange is emitted by QViewManager.versionSelectionChange
		       	  	     QViewManager.redo
				     QViewManager.undo
				     QViewManager.closeVistrail
				     QViewManager.currentChanged
				     QVersionTab.versionSelected

QVersionTab::versionSelectionChange is caught by QVistrailView.versionSelectionChange

QVersionTab::versionSelectionChange is caught by QViewManager.versionSelectionChange

QViewManager::versionSelectionChange is caught by QBuilderWindow.versionSelectionChange

--------------------------------------------------------------------------------

versionWasChanged is emitted by VistrailController.changeSelectedVersion
		     	     	VistrailController.resendVersionWasChanged
				VistrailController.setVersion

VistrailController::versionWasChanged is caught by QPipelineTab.versionChanged

