Separate $JAVA_OPTS for ProcessController and HostController

The way domain.sh and domain.conf work now, whatever value gets assigned to $JAVA_OPTS gets passed to java, so affects the vm used for the ProcessController, and then gets passed through as a param to the PC which uses it for creating the HostController process.

We should have a separate variable for the PC, or perhaps use $JAVA_OPTS for neither and have 2 new variables. Settings for the PC are unlikely to be optimum for the HC, and using the same var makes it harder to set of debugging (e.g. both the PC and HC process will try and use the same port for remote socket debugging.)