Add implementation for methods "isWrapperFor()" and "unwrap()" in JdbcDatabaseMetaData,
JdbcParameterMetaData,JdbcResultSet,JdbcResultSetMetaData,JdbcStatement


git-svn-id: http://h2database.googlecode.com/svn/trunk@5839 e6896862-9d19-0410-bfb3-e9fa5d50e656