Cython mode

Hi, 

This is mostly a request for comment before perfecting this PR.

I'm trying to reuse the tokenisation of python-mode to be reusable in python-like mode, example of cython.
I'm not 100% sure on how to do it, and I used the (undocumented to my knowledge) extra-arg of defineMode to be compatible with auto-load.

In particular, I'm not happy with modifying `parserConf.name`.

Is there a better way to do what I am trying to ? I tried to understand clike mode but was unable to, and I would also like to have something compatible with auto-load, which I wasn't able to do with clike modes.

Thanks a lot.