Commons DBCP Managed Data Sources

This patch changes the "Default JDBC Database" and "Default Unmanaged JDBC Database" to use DBCP for connection pooling. DBCP is the connection pooling code used by many projects like Tomcat and OpenJPA. Once installed all of the properties http://jakarta.apache.org/commons/dbcp/configuration.html can be configured via the normal OpenEJB configuration files.

This patch is contingent on https://issues.apache.org/jira/browse/DBCP-230 being applied and available in the DBCP 1.3-SNAPSHOT jar.