Adding button to modify selection in render view
- Adding a toggle selection mode in render view
- Redesigning pq*SelectionReaction class to generalize part of it in pqGenericSelectionReaction.cxx
- Adding Generic selection modifier button
- Adding use of Ctrl+Shift in render view to use toggle modifier
- Adding separator in title bar to clarify ui
- Modyfying tooltip so it informs user of the key shortcut
Note: The code checking modifier key is NOT shared between Chart and RenderView, because the Char itself is handling it on it's side. trough vtkChartSelectionHelper::GetMouseSelectionMode, may be something smarter can be done here.