fix the deleteCounters bug where packets_received and bad_lines_seen are deleted - cannot ++ an undefined value..

    adjust how we check for the stats counters to support the prefixStats patch - should apply safe with and without the patch

    correct delete_counters unit test to not look for bad_lines_seen of NaN instead look for it set to 1
remove commented lines
Merge branch 'p/deletecounterstatsfix' of github.com:keen99/statsd into fix-statsd-internal-delete-counters

Conflicts:
	stats.js
fix indent
fix syntax
Merge branch 'master' of github.com:etsy/statsd