Database logger in progress

I've payed attention to libdbi, because I'm really like it's database independency and I think this is really what we need :)

On Ubuntu everything is really simple, but for Windows I had some problems.

For building Window's Pidgin we use Cygwin and gcc from MinGW.
Pre-compiled libdbi and libdbi-drivers binaries from the official site are built by Cygwin gcc, so
this libraries are not what we want for Pidgin. Thus we need rebuild them
using MinGW gcc.

After severl days work I got libdbi and mysql driver which needn't cygwin DLLs. So my test example passed successfully.

Now I'm currently working on Windows implementation of Database Logger, but really it doesn't matter, because it'll take a little time to make *nix version.

For simulation of asynchronous work with DB, I've used new thread and mutex for thread synchronization.

For Windows implementation I've choosen glib's threads API. We can do so, because on Windows GTK+ is necessary library