Merge pull request #187 from mreiferson/nsq_stat_errors_187

nsq_stat: error handling
Merge pull request #188 from mreiferson/counter_page_188

nsqadmin: fix counter page
Merge pull request #182 from mreiferson/active_deletion_182

nsqd: deleting a "live" topic
Merge pull request #176 from mreiferson/optimizations_176

nsqd micro-optimizations
show production users in README