Use giflib or libungif to provide GIF support, instead of using internal routines. Delete internal GIF support code with no stated license. Fix up a number of references in the documentation to GIF support. See discussion on xemacs-beta: <87iqg4vg9t.fsf@uwakimon.sk.tsukuba.ac.jp>.

while (<STDIN>) {
  if (/^\$Revision:\s*([0-9\.]*)/) {
    print "char *version = \"$1\";\n";
    print "static char *id = \"\\n%%% setup-version $1\\n\";\n";
  }
}