[WFCORE-452] Parsing and model stage with validation for profile includes
[WFCORE-452] Wire extension resources into host model

This is needed since in order to configure subsystems on a host the
extensions from the domain model have not yet been initialised.
Some logic to make sure that defining extensions in both the domain and
host model is not an error, and to make sure that only the last remove
from the model does the actual removal from the registry.
[WFCORE-452] Share XMLMapper and subsystem writer registry between host and domain

parsers.

Also clean the extension registry properly on reload.
[WFCORE-452] Ugly Hack! Allow turning off looking for profile resource for tests of type HC

Hope to be able to remove this later
[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.

Changing anything in a subsystem at runtime still does not work in
domain mode, since it confuses the ServerOperationsResolver.
MODEL part only