File system bugfixes

git-svn-id: http://h2database.googlecode.com/svn/trunk@5171 e6896862-9d19-0410-bfb3-e9fa5d50e656
Documentation

git-svn-id: http://h2database.googlecode.com/svn/trunk@5172 e6896862-9d19-0410-bfb3-e9fa5d50e656