this is for supporting external plugins.
external plugins will depend on a few telegraf interface types, as well
as a common telegraf registry.
this will allow external and internal plugins to both share this package
and make it easier to vendor/version the whole thing semantically, which
will make it easier to keep plugins supported across build and telegraf
versions.
see #1717
* Add in support for looking for substring in response
* Add note to CHANGELOG.md
* Switch from substring match to regex match
* Requested code changes
* Make requested changes and refactor to avoid nested if-else.
* Convert tabs to space and compile regex once
Also changing the net_response and http_response plugins to only accept
duration strings for their timeout parameters. This is a breaking config
file change.
closes#1214