There is probably a better way of doing this, but currently
parseCustomFile can modify globals (e.g. TOPOS) as well as
instance variables (self.validate) and classes (e.g. MyTopo),
which are also in the global name space.
Inconveniently enough, lambdas don't seem to be full closures
in Python; if they were, this trickiness would be unnecessary.
Even so, using execfile() seems like it might be a bit dubious...
It's possible that mn_clean is a bit easier to read; mnclean may be easier
to type, however.
Added variables to Makefile so that source files are listed in a single
location.
Bob Lantz
Brandon Heller