Puppet 4 support.

Clean up CHANGLOG.

Allow electrical/file_concat version >= 1.0.0.

Update docs.

Merge pull request voxpupuli#270 from elastic/logstash-2.0

Logstash 2.0

Update files for release 0.5.1

Update files for next release

Update for release 0.4.3

Prep files for release of 0.4.2

Update for release 0.4.1