Added dependencies required by ModeShape 3.8 (DV 6.1)

The following artifacts were added:
- `com.datastax.cassandra:cassandra-driver-core`
- `com.drewnoakes:metadata-extractor`
- `com.smartgwt:smartgwt-skins`
- `smartgwt:smartgwt`
- `org.jboss.spec.javax.resource:jboss-connector-api_1.6_spec`

The PR also contains a temporary fix (via a property) for the problem described on the mailing list regarding the enforcer plugin and managed dependencies from profiles. The temporary fix can be removed (if desired) later on, when the plugin is fixed.