Some platforms have GLU libraries that don't behave properly in certain
respects, and some Coin users have particular needs wrt. Coin's use of
GLU. For these users, we (at Kongsberg Oil & Gas Technologies) have
created a fork of SGI GLU 1.3 named SuperGLU that we have tweaked in
certain ways.

This library can be checked out into the Coin source code directory,
which will be detected at configure-time and linked statically into
Coin and used instead of the GLU libraries on the host system.