v3 - no read-write mode for rdbms dataconnector

[Jim Fox]

I have a RelationalDatabase dataconnector for persistent id lookup and 
generation.  It generates them as needed.  For that it needs the database 
connection to be read/write.

I used to be able to set ( readOnlyConnection="false" ) in the 
DataConnector element.  That is still allowed, but seems to have no 
effect.  I tried both the old configuration, ApplicationManagedConnection,
and the new one, BeanManagedConnection.  Both opened the connection 
read-only.  With the bean one I also set ( p:defaultReadOnly="false" ), to 
no effect.

Jim