BUG : correction of the ranges column width

- The tableview width was not updated when the Attributes/ranges tab is not displayed (but the information file one). Therefore, the second column width was miscalculated since it was using this tableview width. WIth this correction, the resizing of the column is called when this Attributes/Ranges tab is selected.
- This column resizing function is the same that will be called when resizing the window or displaying the new range information.
NEW : ColorBar Update to extend range

 A feature as been asked : being able to choose the range of your colorbar. This feature implies that we add a range relative to each attribute/colorbar, that the user could modify, and reset to commonRange, which is the actual real range we used to use.
A structure as been created, colorBarStruct, to replace the colorPointList. This ColorBar contains a colorPointList and a range, that we will load like we used to do with the colorpoints.
Now the range does not automatically adapt to the selected meshes.
ENH multiple things :

- deleted removeArrow() in gradientWidget
- added the bool variable m_updateOnPositionChanged in ShapePopulationQT to avoid unecessary updates when a color arrow is moved
- added the bool variable m_renderAllSelection in ShapePopulationBase to be used anytime something is rendered, to avoid calling RenderSelection() for nothing : way faster!!
- Changed loadVTKfileCLP into loadVTKfilesCLP, seo that using CLP or Drag&Drop, createWidgets is only called once all the files are added to the list : faster loading.
- some work on the display options when loading to load faster, but there is still work to do (looks like it is placing, then resizing, then creating the new Windows, but if there are too much the number of columns changes, and you need to place and resize again... long!!)
- in createWidgets, anytime new vtk are added, the synchronization is set to Delayed, to avoid frozing the software if there are too much points to process.
ENH : loading quicker

- The bool variable m_updateOnAttributeChanged helps not calling  the spinBox_Attribute_indexChanged() when adding every attribute during the createWidget() function
- setting the scrollArea (Display Area) visibility to false when creating widgets, then setting it to true at the end (after placing and resizing) will only render everything at the end.
- also, we set the renderAllSelection variable to false before settinf the visibility to on, to avoid unnecesary rendering.

We know have a very quick loading for multiple meshes!
BUG : colormap loading on dragp&drop + delete selection option

- allow delete selection after loading files for the 1st time
- when loading on drag&drop, does not apply to all attributes anymore but only the active one (workaround to not change the chosenRange to all the attributes ranges). Next step will be including the chosenRange in the .spvcm file to be able to load it too.
ENH : rendering selection enhanced on resizing

- instead of setting m_renderAllselection to false before rendering then to true after it, we are going to set it to true before calling RenderSelection and set it to false after, which will be way convenient to be sure we don't renderSelection for nothing by controling it directly.
- To allow the renderselection when interacting with the mouse, we created two observers on BeginInteraction and EndInteraction on the Interactor, which will respectively set m_renderAllselection to true and false.
Merge branch 'master' into colorbarUpdate