Lumberjack gem patches to support using the protocol as a forwarder between logstash instances

Fix three issues:

1. Client side was dropping non-string data entirely.  Fix deep_keys to handle non-hash instead of just string and hash.
2. Client side was not handling structures nested more than one level deep: a.b.c=1 would be rendered as b.c=1 instead.  The client side counterpart of ([LS-1603](https://logstash.jira.com/browse/LOGSTASH-1603)).
3. Server side was not handling nested structures at all ([LS-1603](https://logstash.jira.com/browse/LOGSTASH-1603)).  Fixed to parse dot-separated fields as nested structures.