Deltacloud client: extract to its own plugin

The deltacloud client currently is hidden in org.jboss.tools.deltacloud.core. In order to have a java client, that deltacloud may offer officially (we already had talks to them), we need to put the client into its own bundle. As bundle, this component may also be used by non-osgi apps since osgi only add additional properties to the manifest which will be simply ignored by non-osgi apps.