Need to decide how to deal with locating resources that may be relative to some other concept that the project (e.g. Java classes relative to classpath).
The physical resource is still relative to the project, but some models may need to refer to the resource based on its native relative location.
For example, to locate a Java file in the model repository, we use the full path. However if another model wishes to be dependent on the Java class, and not specifically on that Java file resource, then it will be dependent upon the package/classname relative to the Java classpath.
One possibility is that the Java classpath relative model reference is treated as an 'interface' of the actual resource - i.e. the resource file is an implementation of the classpath relative model reference.