[gnome-db]MySQL provider

[Vivien Malerba <malerba TorresQuevedo HispaLinux es>]

Hi!

I've made some work on the MySQL provider to make it provide
a data types list, and more is on the way for functions and 
aggregates.

I have not yet commited the changes because I first wanted to know
if some people are currently working on it. Can you tell
me if that is the case, or if I can commit the work?

I plan to work on the Postgres and MySQL providers to bring
them at the same level (gASQL has taken me a lot of time to
release the latest version!).

Cheers,

Vivien