closes #2339

Also, ensure pidfile perms are 644

closes #1516 
closes #1711 
closes #1721 
closes #1526 

* Procstat: don't cache PIDs

Changed the procstat input plugin to not cache PIDs. Solves #1636.
The logic of creating a process by pid was moved from `procstat.go` to
`spec_processor.go`.

* Procstat: go fmt

* procstat: modify changelog for #2206

closes #2244
closes #1547

this defer function was causing telegraf to call os.Exit(0) instead of
panicking when it was supposed to.

closes #2341

closes #2356

* ceph: maps are already refs, no need to use a pointer

* ceph: pgmap_states are represented in a single metric "count", differenciated by tag

* Update CHANGELOG

* Update README.md

* Add lock support to the IPtables input plugin

* Update iptables.go

Doc cleaning

* 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

* Keep -config-directory when running as Windows service

* Update changelog

* Make Logparser Plugin Check For New Files

Check in the Gather metric to see if any new files matching the glob
have appeared. If so, start tailing them from the beginning.

* changelog update for #2141

closes #2324

fixes #2317

closes #1453
closes #1386
closes #1428

* rename to riemann_legacy

Signed-off-by: Fabio Berchtold <fabio.berchtold@swisscom.com>

* initial draft for Riemann output plugin rewrite

Signed-off-by: Fabio Berchtold <fabio.berchtold@swisscom.com>

* add unit tests

Signed-off-by: Fabio Berchtold <fabio.berchtold@swisscom.com>

* add option to send string metrics as states

Signed-off-by: Fabio Berchtold <fabio.berchtold@swisscom.com>

* add integration tests

Signed-off-by: Fabio Berchtold <fabio.berchtold@swisscom.com>

* add plugin README.md

Signed-off-by: Fabio Berchtold <fabio.berchtold@swisscom.com>

* bump riemann library

* clarify settings description

Signed-off-by: Fabio Berchtold <fabio.berchtold@swisscom.com>

* update Readme.md with updated description

Signed-off-by: Fabio Berchtold <fabio.berchtold@swisscom.com>

* add Riemann event examples

Signed-off-by: Fabio Berchtold <fabio.berchtold@swisscom.com>

* use full URL for Riemann server address

Signed-off-by: Fabio Berchtold <fabio.berchtold@swisscom.com>

closes #1878

This changes the current use of the InfluxDB client to instead use a
baked-in client that uses the fasthttp library.

This allows for significantly smaller allocations, the re-use of http
body buffers, and the re-use of the actual bytes of the line-protocol
metric representations.

closes #2256

The changes in #1848 resulted in lines being dropped if they had an empty
tag. Let's allow all lines that have empty or missing tags!

Fixes #2106

We were having problems with telegraf talking to
carbon-relay-ng using the graphite output. When
the carbon-relay-ng server restarted the connection
the telegraf side would go into CLOSE_WAIT but telegraf
would continue to send statistics through the connection.

Reading around it seems you need to a read from the connection
and see a EOF error. We've implemented this and added a test
that replicates roughly the error we were having.

Pair: @whpearson @joshmyers