While writing gtkdlg.c I learned how to specify a window's initial

While writing gtkdlg.c I learned how to specify a window's initial
position in GTK, so I can now implement the other half of -geometry
which I'd previously believed to be impossible in GTK. It's still
not perfect, because GTK apparently provides no way for us to get
hold of the X reparent event in order to support negative geometries
in a manner which takes account of the WM borders; but for positive
position it's at least an improvement on the previous version!

git-svn-id: svn://svn.tartarus.org/sgt/putty@3078 cda61777-01e9-0310-a592-d414129be87e