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
    add config (deleteIdleStats) to delete idle sets, gauges, timers - and a overall flag to set them all but allow individual overrides
    update delete_counters unit test to test deleteIdleStats which covers all stat types
update readme and example for deleteIdleStats and friends
reorder example for easier merge
reorder example for easier merge
remove commented lines
Merge pull request #251 from Dieterbe/master

clearer sample graphite url
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
Remove extra Object.keys check in the timer_data loop
Merge pull request #255 from etsy/optimize-graphiteBackend

Remove extra Object.keys check in the timer_data loop
Add support for gauge deltas.

* Add tests for gauges and new gauge deltas.
* Add support for +/- prefix for gauge values to support modifying
  gauge values in-place.
Remove numStats asserts.
Merge pull request #72 from jsocol/modify-gauge

Add support for gauge deltas.
Update readme with gauge delta info.
Merge pull request #256 from jsocol/gauge-readme

Update readme with gauge delta info.
remove duplicate code, and fix global leak
pulled out the wrong set