Add per method rate limit.

Allow users to set the rate limit factor per method, Ex. you could set "account-v1.getByPuuid" to have a usage factor of 0.5 which would mean that it would use up to half the rate limit on just that method. This would probably override the method_rate_limit. It could overwrite the app_rate_limit or multiply against it not sure, and for the over all rate limit it would probably multiply against it.
