closes #2356

closes #1113

changes:

- -sample-config will now comment out all but a few default plugins.
- config file parse errors will output path to bad conf file.
- cleanup 80-char line-length and some other style issues.
- default package conf file will now have all plugins, but commented
  out.

closes #199
closes #944

The following configuration is now possible

	## CompressionCodec represents the various compression codecs
recognized by Kafka in messages.
	##  "none" : No compression
	##  "gzip" : Gzip compression
	##  "snappy" : Snappy compression
	# compression_codec = "none"

	##  RequiredAcks is used in Produce Requests to tell the broker how
many replica acknowledgements it must see before responding
	##  "none" : the producer never waits for an acknowledgement from the
broker. This option provides the lowest latency but the weakest
durability guarantees (some data will be lost when a server fails).
	##  "leader" : the producer gets an acknowledgement after the leader
replica has received the data. This option provides better durability
as the client waits until the server acknowledges the request as
successful (only messages that were written to the now-dead leader but
not yet replicated will be lost).
	##  "leader_and_replicas" : the producer gets an acknowledgement after
all in-sync replicas have received the data. This option provides the
best durability, we guarantee that no messages will be lost as long as
at least one in sync replica remains.
	# required_acks = "leader_and_replicas"

	##  The total number of times to retry sending a message
	# max_retry = "3"

Also normalize TLS config across all output plugins and normalize
comment strings as well.

closes #599

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

With the advent of Kafka 0.9.0+ it is possible to set up TLS client
certificate based authentication to limit access to Kafka.

Four new configuration variables are specified for setting up the
authentication. If they're not set the behavior stays the same as
before the change.

closes #541

Fixes #280
Fixes #281
Fixes #289

closes #200

Closes #167

Closes #38