Needed as part of the fix for Issue #1690
Needed as part of the fix for Issue #1690

* build/ac-macros/swig.m4
  And here's the rest of Ben Reser's correction to my SWIG_VERSION fix.

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion