SWITCHYARD-2415 StackOverflowError thrown when service with selfrefering...

StackOverflowError thrown when service with selfrefering implementation property is deployed.

@errantepiphany : Am I on the right track here?   I couldn't find a way of checking the unresolved value of the property unless I added a method to configuration that returned an attribute unresolved.     

The SystemResolver always tries to resolve before the ComponentModel, right?  I don't want to be throwing RuntimeExceptions if the property is going to resolve by system env variable.