This runtime will be the uberjar++ arrangement with a
gateway class that will build out the classpath and offer up the
options to X number of main methods.
The RuntimeClassLoader is meant to be used inside of a jar file and takes in a
Runtime object (as defined by the runtime mojo, not the System Runtime) and
uses the dependencies specified in it to construct references to jar files
inside of that jar file.
The simplest type of runtime descriptor that can be
processed, intended to generate just the bare bones of a runtime
environment, perhaps not even enougth to bundle up.