General Fixes and Enhancements

* Increment cookbook version to 1.4.0
* Upgrade to Beaver version 31
* Include logstash_version = 1 as default config option
* Allow Beaver to be run as a non-root custom user (defaults to root for backwards compatibility)
* Improve beaver_tail resource
  * add support for multiple file paths
  * add support for multiline_regex_after and multiline_regex_before
  * cleanup up empty fields being output from template