Adding parameter-based ability to resolve expressions via management API and CLI commands

https://issues.jboss.org/browse/WFLY-1069
The help content for this command has to be updated too to include this argument with at least a brief explanation of when it is allowed and when isn't.
The same has to be done for org.jboss.as.cli.handlers.ReadAttributeHandler.
I imagine you are fed up with this issue now :) Well, you can get it done to certain point and I'll complete what's left, if you like. Thanks for your efforts :)