[WFCORE-452] Make ExtensionRegistry a bit more lenient when looking for

the profile resources. In a proper domain these will always be set up,
but there are some tests where the process type is HOST_CONTROLLER where
they are not.
[WFCORE-452] Register profile resource definition in domain model, as part of host model

init so extensions get properly registered at host boot.
[WFCORE-452] Add support for SubsystemRegistration.setHostCapable()

Extensions calling this get the resource definitions for these subsystem
registered in the host model, in addition to in the usual domain model
profile.
[WFCORE-452] Add OperationContext.isRegisterDeployers()

Throw exception if deployers are attempted added from a subsystem
installed on the HC.
[WFCORE-452] Support for configuring/persisting subsystems in host.xml.

MODEL part only
[WFCORE-452] Add first version of OC helper methods to determine if runtime step should run

Modify Abstract- Add-/Remove-/WriteAttribute Handlers to use the new
helper method.
[WFCORE-452] Rework ModelControllerServiceInitialization to boot op.

Previously the ModelControllerServiceInitialization loading was
hardcoded as part of the boot sequence. However, in order to use JMX as
a subsystem on the HC we need access to the services started by JMX's
MCSI. Putting these earlier also does not work, since patching's MCSI
needs to read values from the model, which do not get set until the boot
time. Hence this initialization has been refactored to an extra boot
RUNTIME step which has access to the model, and is able to install the
services JMX needs on a host.
[WFCORE-452] Determine if we are a master/slave before extensions are registered
[WFCORE-452] Get jmx working as a HC subsystem

Remove the hardcoded/duplicated HC RemotingConnectionService. We can now
configure it in host.xml.
Take into account whether we are a master or slave. Only master should
be able to modify attributes and add mbeans in the domain model.