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
* Allow for TLS connections to ElasticSearch
Extremely similar implementation to the HTTP JSON module's
implementation of the same code.
* Changelog update
This constitutes a large change in how we will parse different data
formats going forward (for the plugins that support it)
This is working off @henrypfhu's changes.
This will basically make the root directory a place for storing the
major telegraf interfaces, which will make telegraf's godoc looks quite
a bit nicer. And make it easier for contributors to lookup the few data
types that they actually care about.
closes#564