Log Message:
Fix location of temporary files, as they were beeing created under / instead
of /tmp!  If you have been using GNOME, you may want to 'rm -f /.fam*' to
clean them up.

The problem is caused by two different issues, related to a call to tempnam:

- The code uses a HAVE_UNSETENV define to check if the unsetenv function
  is available; however, the configure script does not check for it, so
  unsetenv is never used.  Fix the configure script to check for unsetenv.

- If unsetenv is not available, it does putenv("TMPDIR=") before calling
  tempnam.  The code expects that this call *unsets* the variable from the
  environment (which happens in Linux), but instead it is *set* to an empty
  value, causing the creation of files in the root directory.  Fix this by
  explicitly setting TMPDIR to /tmp.

Bump PKGREVISION to 1.