Fix for bug 203 - DESTDIR brokes installation

See http://bugs.mercury.csse.unimelb.edu.au/view.php?id=203
Stripped DESTDIR when building boehm_gc/libatomic_ops
Added DESTDIR to default values in scripts/mmc
Allow /usr/lib64 override (bug259)

Many linux distributives uses /usr/lib64 for amd64 libraries and
/usr/lib32 for x86. To support those this change allows to override
/usr/lib with standart libdir var in autoconf.

See http://bugs.mercury.csse.unimelb.edu.au/view.php?id=259
Add man, info and lisp dirs configuring (bug259)

See http://bugs.mercury.csse.unimelb.edu.au/view.php?id=259
fix race condition