Make sure the __MWERKS__ test can't go unnoticed. It's really time to

Make sure the __MWERKS__ test can't go unnoticed. It's really time to
remove all those 41 hacks if possible. Metrowerks is under category
"Defunct software companies" in Wikipedia, its compiler was known to
work on PowerPC (which we don't support, anway, right?) and on some
Unices. The hacks are in CVS since the first commit 2002/9/10 (old
repository!) and probably were in the code long before that. Any
platform where such a broken compiler is still used, will hardly
be suitable to run fgfs at all.