[glade--]Is it easy to have a glademm project with classes in subdirs?

If you have a glademm project, is it easy to set up the makefiles to
handle subdirectories?  When you get a lot of classes it starts to
become a lot to look at, and it would be nice to put some in
subdirectories of the src directory.  I'm not really talking about the
classes generated by glade, but supporting classes written by hand.

This is not necessarily a glademm specific question, but I am
considering it to be somewhat because of the makefiles being created by
the autogen.sh script written by glademm (and autoconf/automake).  So
the makefiles are somewhat a function of the handy work of glademm.  I
figure maybe someone on this list might have attempted this either
successfully or not.

Mark