Added write_consistency to InfluxDB output documentation

closes #1278
closes #1277

Allow using glob pattern in the command list in configuration. This enables for
example placing all commands in a single directory and using /path/to/dir/*.sh
as one of the commands to run all shell scripts in that directory.

Glob patterns are applied on every run of the commands, so matching commands can
be added without restarting telegraf.

closes #1142

closes #1275

closes #1265

closes #1272

closes #1264

closes #1268

closes #1258

* Use shared AWS credential configuration.

*  Cloudwatch dimension wilcards 

* Allow configuring cache_ttl for cloudwatch metrics.

* Allow for wildcard in dimension values to select all available metrics.

* Use internal.Duration for CacheTTL and go fmt

* Refactor to not use embedded structs for config.

* Update AWS plugin READMEs with credentials details, update Changelog.

* Fix changelog after rebasing to master and 0.13.1 release.

* Fix changelog after rebase.

closes #1221

Replace ":" with "_" in tags. This should make the mysql plugin work with the opentsdb output (it uses a "server" tag like "127.0.0.1:3306") (#1256)

* Report rollbar events.

Signed-off-by: Cyril Duez <cyril@stormz.me>
Signed-off-by: François de Metz <francois@stormz.me>

* Fix indent with go fmt.

* Add test for rollbar webhooks.

* Report more data from new_item event.

* Handle new deploy webhook.

Signed-off-by: Cyril Duez <cyril@stormz.me>
Signed-off-by: François de Metz <francois@stormz.me>

* Update default port.

* Add readme.

* Add rollbar_webhooks to the readme.

* Add rollbar_webhooks to plugins list.

* Add tag level for new_item event.

* Update readme.

* Update changelog.

* Adding Varnish HTTP Cache input plugin

* Applying PR feedback

- Linked to varnish in input README
- Updated README/CHANGELOG
- Cleaned up sampleConfig to remove formatting
- Shorted lines to 80 chars (except where test input requires long strings)
- Using internal.RunTimeout to wrap call to varnishtat
- Added dummy file for windows

closes #1249

* add chrony support

* remove path definition

* add changelog

closes #1243

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

This update adds support for strings values. Not sure why this was missed.

* Fix a typo.

* Extract similar code to generateEvent function.

* Remove functions to use generateEvent in the switch.

* Refactor tests.

closes #1190

Changing the internal behavior around running plugins. Each plugin
will now have it's own goroutine with it's own ticker. This means that a
hung plugin will not block any other plugins. When a plugin is hung, we
will log an error message every interval, letting users know which
plugin is hung.

Currently the input interface does not have any methods for killing a
running Gather call, so there is nothing we can do but log an "ERROR"
and move on. This will give some visibility into the plugin that is
acting up.

closes #1230
fixes #479

closes #1215

closes #1233

closes #1198

closes #1227
closes #1210

Being able to override the process_name in the procstat module
is useful for daemonized perl, ruby, erlang etc. processes. This
allows for manually setting process_name rather than it being set to
the interpreter/VM of the process.

closes #1223

closes #1211

closes #1221

- records metrics from the output of mon and osd socket perf
  dumps.