new MySQL provider

[Rodrigo Moya <rodrigo linuxave net>]

Hi all!

I've successfully implemented the first provider to make use of the
libgda-server. It is still buggy in some places, and misses several
things, but the basic stuff (connect, send command, and disconnect)
works pretty well. But as MySQL support was really buggy before, this is
a step forward rather than backward.

PS: sorry Chris, for doing so without telling you before, but the old
MySQL provider was really buggy and very bad organized, and this is why
you didn't understand how it worked. But now, you can get it again. I
think you'll find the gda-server lib pretty easy to use.