Bug fix in Ant task database type dropping connection props when used as reference.

I found a bug in the new Ant tasks where a ```<database>``` type created with connection properties then referenced in a task were not adding the properties to the JDBC connection as intended. This is because the ```DatabaseType``` class was not calling a accessor method that would check to see if the type was a reference.
I have updated the ```DatabaseType``` to use a new accessor method that makes it more consistent with all of the other fields in the class.