Remove bug that nulled the name of non-pre-resolved plugins.
Fix name resolution bugs.

1. Fix bug preventing plugins that aren't predefined from failing.
2. Stop using require() to fetch plugin module since it's been cached.  This also works-around the need for an ES6 Loader side registry.
Inject loader into factory.
Revert to older global Module() function from loader.newModule() until we finish updating rave to latest spec.