JAVA_HOME now set in dcs-config.sh

The bin/dcs-config.sh script didn't recognize Java 1.7. Both bin/start-dcs.sh
and bin/stop-dcs.sh now use hostname -f when comparing zkutil returned value
to that of hostname.

Change-Id: Ie0a6937099adf5a43cf890ea050b30ba1df066ff
Closes-Bug: 1369686