Rate-limiting, updating urls, and adding more functions.

*Implemented rate limiting using SplQueue. NOW REQUIRES PHP >= 5.3.
*Fixed call ur's to be more recent.
*Added getLeague() call.
*added getChallenger() call.
*added getSummonerId() call.
*Format_url now allows for additional arguments to be queried in the
call. Example -- if you call /league/challenger?type=RANKED_SOLO_5x5,
you don't get an error saying "missing API key".
*replaced file writing code with simple file_put_contents() call.
*added a debug() function for recursively printing a json_decode'd
array.