Put back <resource-ref>
- It isn't necessary with Tomcat.
- But is necessary with other app servers, including JBoss.
Remove default in code to allow a property value to be ""
 - Otherwise, the default non-empty value is used.
 - In general, we don't want defaults to be in the code, but in properties.
Forwarding cookies isn't necessary since we use internal requests
- And this causes strange issues with eXist creating data as admin/dba.
Minor: some rewrite for clarity
Owner/group permission for eXist, fix #1341