This ensures that they will pick up updates to their parent methods
without having to add any code. In particular, git-svn and emacsmirror
will automatically pick up the new git checksum method.
This includes teaching methods that they now work with a symbolp PACKAGE,
some more cleaning up, and some load-path adjustments now that a part of the
code is in a subdirectory (methods).
Also include some of the tests used to convince oneself that the refactoring
didn't break any and all use cases for el-get, with some rough documentation
about how to use them.
