Revert "fix gv-3.7.4 compile error with old versions of Xaw3d"

This breaks "./bootstrap" on my system (CentOS 5).

This reverts commit c1f72b64d6617303ca2b4a3209a1145ac8741f2a.
Reapplied changes from last commit in src/
Update GNULIB to cdceb2fe48e39f4fff25f6f4cb34bbab88c2856f