Add a 404 and high-traffic test to http listener

also remove locking around adding metrics. Instead, keep a waitgroup on
the ServeHTTP function and wait for that to finish before returning from
the Stop() function

closes #1407

CHANGELOG.md

@@ -17,6 +17,7 @@
 - [#1542](https://github.com/influxdata/telegraf/pull/1542): Add filestack webhook plugin.
 - [#1599](https://github.com/influxdata/telegraf/pull/1599): Add server hostname for each docker measurements.
 - [#1697](https://github.com/influxdata/telegraf/pull/1697): Add NATS output plugin.
+- [#1407](https://github.com/influxdata/telegraf/pull/1407): HTTP service listener input plugin.
 
 ### Bugfixes
 
@@ -91,17 +92,6 @@ consistent with the behavior of `collection_jitter`.
 - [#1434](https://github.com/influxdata/telegraf/pull/1434): Add measurement name arg to logparser plugin.
 - [#1479](https://github.com/influxdata/telegraf/pull/1479): logparser: change resp_code from a field to a tag.
 - [#1411](https://github.com/influxdata/telegraf/pull/1411): Implement support for fetching hddtemp data
-- [#1407](https://github.com/influxdata/telegraf/pull/1407): HTTP service listener input plugin.
-
-### Bugfixes
-
-- [#1384](https://github.com/influxdata/telegraf/pull/1384): Fix datarace in apache input plugin.
-- [#1399](https://github.com/influxdata/telegraf/issues/1399): Add `read_repairs` statistics to riak plugin.
-
-## v1.0 beta 2 [2016-06-21]
-
-### Features
-
 - [#1340](https://github.com/influxdata/telegraf/issues/1340): statsd: do not log every dropped metric.
 - [#1368](https://github.com/influxdata/telegraf/pull/1368): Add precision rounding to all metrics on collection.
 - [#1390](https://github.com/influxdata/telegraf/pull/1390): Add support for Tengine