* Trim null characters in Value data format

Some producers (such as the paho embedded c mqtt client) add a null
character "\x00" to the end of a message.  The Value parser would fail on
any message from such a producer.

* Trim whitespace and null in all Value data formats

* No unnecessary reassignments in Value data format parser

* Update change log for Value data format fix

* added connection Timeout parámeter, basic HTTP autentication and HTTP support with Sslskipverify option

* updated README.md

* added optional SSL config , changed timeout name and type , and other minor fixes

* added some code style improvements

* Update README.md

* Cache and expire metrics for prometheus output

* Fix test

* Use interval.Duration

* Default prometheus expiration interval to 60s

* Update changelog

* patching udp_listener for fun

updating with errcode

adding debug flags to temp msgs

moving from debug to info

* updating PR 1883 based on feedback

Fix single quote parsing of TOML durations

closes #2023

- fully document aggregator and processor plugins
- improve readme.md

closes #1989

Also don't use named returns in fetchNamespaceMetrics since it's
non-standard for the rest of the codebase.

closes #1564

also add unit and benchmark tests

I think this is a copy paste bug? ;-)

primarily for a fix in Windows network counter getting code

closes #1949

Typo

fixes #1956

closes #1936

* NATS output plug-in now retries to reconnect forever after a lost connection.

* NATS input plug-in now retries to reconnect forever after a lost connection.

* Fixes #1953

fixes #1933

closes #1925

closes #1926

in this commit:

- chunks out the http request body to avoid making very large
  allocations.
- establishes a limit for the maximum http request body size that the
  listener will accept.
- utilizes a pool of byte buffers to reduce GC pressure.

feat(kubernetes): Add kubernetes input plugin

closes #1774

closes #1742

The MySQL DB driver has it's own DSN parsing function. Previously we
were using the url.Parse function, but this causes problems because a
valid MySQL DSN can be an invalid http URL, namely when using some
special characters in the password.

This change uses the MySQL DB driver's builtin ParseDSN function and
applies a timeout parameter natively via that.

Another benefit of this change is that we fail earlier if given an
invalid MySQL DSN.

closes #870
closes #1842

closes #1344