Work around broken Marble on Debian

This is a major hack. Debian appears to be missing a necessary header file
for Marble to work correctly. We include this header file for now and hack
the Configure process to recognize that we are on Debian and force using
our local copy of the header file in that case.

This may be needed on Ubuntu as well.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>