Loading of Ecore models depends on side effects

[tvdstorm]

To reproduce:

• load Ecore from http://www.eclipse.org/emf/2002/Ecore (get FileNotFound)
• load local model (e.g., MyFSM or something) from file, (success)
• load Ecore again, now it works.

[tdegueul]

Related to the classpath problems I guess.

Ecore is registered in Eclipse's EPackage.Registry at startup time, but the Rascal console creates another EPackage.Registry in a different classpath, so it does not work the first time.

Loading any model will register Ecore in the registry if it's not there already, so it will work the second time.