using spl_autoload_register instead of __autoload for compatibility

A quick fix for the bigger problem of the project not being PSR-0. PSR standards didn't exist when it was written so no hard feelings. I might come back soon and PSR-0 the hell out of it :)
Merge pull request #10 from mattpotts/patch-1

using spl_autoload_register instead of __autoload for compatibility