Added some documentation in the README and javadoc comments for the PinPaymentsService methods.  Removed the deprecated findAllSubscribers method since there is no point in leaving in the published version of the plugin.  Added featureLevel parameters to a couple of methods where the value was hard coded which doesn't make any sense.  Removed _ from some parameter names and updated the message body closures so they continue to work.  Renamed findSubscriber to getSubscriber, findAllSubscriptionPlans to getSubscriptionPlans, findSubscriptionPlan to getSubscriptionPlanById and findSubscriptionPlanByName to getSubscriptionPlanByName.  Updated the subcribeToFreeTrial method signature to be consistent with the other methods.  Updated the PinPaymentsTagLib namespace to "pinpayments" instead of "spreedly".