applied AwsConfig mixin to all AWS plugins
Merge branch 'master' into aws-iam-roles
added old config options for backward compatibility with deprecation warnings & info
added conditional around compatibility code
added a missing deprecated flag
moved call to setup_aws_config to mixin
Merge branch 'master' into aws-iam-roles
Add JSON encoder filter.
Add agent configtest option for use when verifying logstash config files prior to restarting the logstash service
Add agent configtest option for use when verifying logstash config files prior to restarting the logstash service
Revert "Add agent configtest option for use when verifying logstash config files prior to restarting the logstash service"

This reverts commit 5658d3658b45d1127f07aeb30bd3b03f0ea857ce.
Revert "Add agent configtest option for use when verifying logstash config files prior to restarting the logstash service"

This reverts commit 2c2b076129c30c9c17f8d6d5507e778c6169e407.
Added configtest option
Fixes for LOGSTASH-827 and LOGSTASH-841
Adding a solution for testing output/email using rumbster (https://github.com/aesterline/rumbster)
Fix and test for LOGSTASH-559 authenticationType=>nil
New task to create a JIRA Component per plugin
Merge pull request #381 from wiibaa/emails

Rebase PR-337 Emails output Fixes: LOGSTASH-827 and LOGSTASH-841
Merge pull request #382 from wiibaa/jira

New task to create a JIRA Component per plugin
Refactoring

- Replace fields and container with source and target
- Add tests for the new variables
minor doc adjustment