Apply windows hack in {{{svn_fs}}} unit tests only when running on windows. Older repositories may not have a {{{db/format}}}} file, so check whether it exists before doing a {{{chmod}}}.
Apply windows hack in {{{svn_fs}}} unit tests only when running on windows. Older repositories may not have a {{{db/format}}}} file, so check whether it exists before doing a {{{chmod}}}.

git-svn-id: 0d96b0c1a6983ccc08b3732614f4d6bfcf9cbb42@1916 af82e41b-90c4-0310-8c96-b1721e28e2e2

rbaumg/trac,rbaumg/trac,rbaumg/trac,rbaumg/trac