util: Pass full json_rpc_call_state to upload_data_cb
Avoid retrying longpoll requests for removed pools (and possibly change block change notification source for existing ones) if longpoll connection gets dropped
Track which pools have active longpoll connections
pool_active_lp_pool function to complement select_longpoll_pool
If the current pool lacks its own block change detection, keep the pool used for that connected
Merge branch 'lp_refactor_201405' into bfgminer