[metapost] new MetaPost tutorial to spread

[Clément Hurlin]

> Very nice.
> Can you tell me where to find the package "smelc.sty" used in your TeX
> file? Thanks.
Thanks,
You don't need it and can remove the \usepackage{smelc} line, it will compile 
without problems.
It's where I put my personal definitions, but the tutorial doesn't use it. 
Thanks for letting me know, I've fixed the sources.

Regards,
Clément