Pipelining of requests to improve throughput
     -- new parameter max-pipelined-requests (default 20) for maximum number of requests to batch at one time

   Deletion of counter keys when zero
     -- new parameter delete-when-zero (default false) to enable.  This will cause a redis eval to execute to decrement counters instead of DECR.

   Detection of negative limit counters
     -- Self healing of negative counters (due to key eviction, etc)