Document the workaround for the diff_cmd vs. diff-cmd inconsitency.
Document the workaround for the diff_cmd vs. diff-cmd inconsitency.

* www/project_faq.html: New FAQ in the Troubleshooting section:
"I get exitcode 2 from diff3 on Windows"

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