Added seedrandom.js dependency ( work from David Bau ). Later i will push another version without this dependency.

Ok, a lot of work on armor() and a little of refactoring, little clean ups and little optimization.. Created a new standalone method for d20 game systems and a lot of documentation on process ( i´m very lazy for that),
and i promise... index.html and main.js cleanup for a better and more explicative's examples...