Revision 2761

* Thuban/UI/mainwindow.py: Refactored, now the build-in function map()
can be used again:
a) renamed local variables map to mymap. It was covering up map().
b) removed calls filling  map = self.Map() in
DatabaseManagement()and LayerProjection() as the result was not
used and MapCanvas.Map() does not have a side effect.