Added Monty-Hall, 100doors, 99 bottles, SOR and Gauss-Seidel

Hi all,

I added the following algorithms implementations in Lua:
* [Monty-Hall problem](http://en.wikipedia.org/wiki/Monty_Hall_problem)
* [100 doors problem](http://rosettacode.org/wiki/100_doors)
* [99 bottles of beer song](http://99-bottles-of-beer.net/lyrics.html)
* [Successive Over Relaxation algorithm](http://en.wikipedia.org/wiki/Successive_over-relaxation)
* [Gauss Seidel algorithm](http://en.wikipedia.org/wiki/Gauss%E2%80%93Seidel_method)

Tests have also been included, as usual. I also added some tags.

Regards,
Roland.