Module prepend

Still two failures to work out, but it mostly works.

Don't pull until this is worked out. There might be dragons hiding in those last two.

Module#prepend prepends multiple modules in the right order FAILED
Expected [:c, :m1]
 to equal [:c, :m2, :m1]

Module#prepend works with subclasses FAILED
Expected [:class, :subclass]
 to equal [:class, :module, :subclass]