Glom port to gtkmm2

After a year or so of occasional porting while I waited for other stuff to compile, I finally finished porting Glom to gtkmm 2. This one has much simpler dependencies, with no need for Xerces-C++ or gnomemm or GtkExtra–. There is now a slim chance that I might actually start adding functionality to it, though I’d like to explore use of libgda instead of just using MySQL

glibmm and gtkmm 2.4 are in gnome’s cvs, with those module names, and pretty much ready for release as soon as glib and GTK+ 2.3.0 versions are released.

Now it’s just orbitcpp that still needs work.