Deb package creation script

This script makes a .deb package out of FreeCAD source. You need the checkinstall package installed. To use it, just:
 * edit the script and change manually the config lines if needed
 * copy it to your freecad source dir,
 * make it executable,
 * make sure your source will compile without errors (do a "make" first),
 * then run the script.