Clarify/extend/simplify File->Save As vs. View->Save As
Users seem confused by the two ways to save data: either with File->Save As or View->Save As.
The underlying idea is simple: "File" works on GModel, "View" works on PView. However, just doing "File->Save As" and entering a file that ends with .pos will create a mesh statistics post-processing view, which is probably not what the user wanted: he/she probably just wanted to save the currently visible post-processing view to disk...
What we could do: provide File->Save As->Post-processing View + a small window with