Creation of subsystem framework

ASTools has a requirement for mixin-style behavior. The current similar API is called the BehaviorModel, however it does not allow for mixin-style behavior. The server can be in only 1 mode at any time, and so therefore can have only 1 set of systems at any time, and there are currently only 2 sets: a local set, and an rse set.

The contents of these sets change based on server version, so for example, AS 6 in 'rse' mode may stop with a java command to the shutdown jar launched over a remote shell, while Wildfly 8 will shutdown with a call to management.

A model needs to be created to resolve and load arbitrary systems, even those not declared by ASTools directly, or allow alternate implementations of the common systems for server types such as OpenShift or Teiid Designer.