Fix test failures in non-English locale.
Fix test failures in non-English locale.

* subversion/tests/cmdline/svntest/main.py: Set C locale.

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