Made boost::shared_ptr<ranged_block_ids_t> be std::shared_ptr<ranged_block_ids_t>.
Made boost::shared_ptr<json_stream_t> be std::shared_ptr<json_stream_t>.
Made us use std::shared_ptr<json_adapter_if_t> instead of boost::shared_ptr.
Made us use std::shared_ptr<js::runner_t>.
Made use of std::shared_ptr<http_conn_t>.
Reverted all boost::shared_ptr -> std::shared_ptr stuff (because boost::program_options uses boost::shared_ptr whyy whyyyy whyyyyyy did we ever decide to use it).