Many of the examples provided within documentation are using a single
dash for the command line arguments, but the telegraf executable
explicitly has two dashes.
There are also some inconsistencies with the ordering of the command
line argument examples. I've ordered them so that the examples will
show: config, config-directory, input-filter, test
* 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.