For Macs, when GSI is enabled, use 'lib' as the Globus directory even
on 64-bit hosts.  For other OSes, continue to use lib or lib64.

This was suggested by Petr Danecek on irods-chat.


git-svn-id: svn://irodssvn.ucsd.edu/trunk@5584 ea137bd6-aa86-47b6-b90d-b101d9f19a90