<ticket>#454</ticket>
<ticket>#454</ticket>

--
Fixed TransferFunction Widget problem

vistrails/packages/vtk/tf_widget.py
  Added GLOBAL_SCALE variable to control the scale of the scene.
  Before the code behave as GLOBAL_SCALE == 1.0. Now it is set to 4000.0

  class TransferFunctionPoint:
     Scale pen width of selected nodes according to GLOBAL_SCALE
     Setting initial position according to GLOBAL_SCALE

     refresh()
       scaling size of node acccording to GLOBAL_SCALE

     itemChange()
       Considering that point positions are set in scene coordinates.
       When setting transfer function we will scale them down to [0:1].

     added paint() method so we skip the default square Qt draws for
       selected items.

  TransferFunctionPolygon.setup()
     gradient coordinate system should be set according to object

  class TransferFunctionLine:
     setup()
      taking GLOBAL_SCALE into consideration when drawing lines

     mouseDoubleClickEvent()
        when creating a tf point, making sure to scale them down to 0 to 1.

  TransferFunctionScene.__init__()
        drawing the grid taking the GLOBAL_SCALE into consideration

  TransferFunctionView.resizeEvent()
      The matrix is reset according to GLOBAl_SCALE

  TransferFunctionWidget.__init__()
      Seting maximumHeight as the widget will try to use the scene height

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