Fix DBCP-234
The default values for readOnly, autoCommit and transactionIsolation are now taken from the JDBC driver. No calls to setReadOnly(), setAutoCommit() or setTransactionIsolation() will be made for a newly borrowed connection unless a default is explicitly configured (and the connection is currently using a different setting). 

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/dbcp/trunk@1567033 13f79535-47bb-0310-9956-ffa450edef68