[weld-dev] maybe add an ExtensionLoaderService to weld-core?

I've been playing with weld-test, and it'd be neat if a test could specify which Extensions it'd like to use (in an annotation or via dsl-ish config). But it seems WeldBootstrap is directly using a DefaultServiceLoader to find them. So, could this be abstracted into an ExtensionLoaderService interface / DefaultServiceExtensionLoaderService impl? Then tests could set up their own ExtensionLoaderService. -Matt