logstash: Update filters for sending to es 2.x
Post process logs to make them es 2.x compatible:
- converts dot's in the properties into underscores.
- Normalizes the pid and line fields into int. Some of the log types for nodejs services auto-created these as strings.
- Drops the extra timestamp field. @timestamp is definitive, and this timestamp field is seen sometimes as a date, sometimes as a string in the auto generated mappings.
This needs to be tested on beta cluster before being merged.