Chunked messages header fix

[narkisr]

Iv fixed the chunked header implementation for graylog2-server, the current gelf4j implementation uses 36 characters for the header while the current spec supports only 12, iv followed the same algorithm as the gelf4r implementation (using md5 on the current time) and verified the the graylog2 server works,

Best regards Ronen

[narkisr]

Note that I didn't cleanup much, just illustrated a possible solution, also in further commits iv cleared some printing

ef199d906346ae7005dcffd397b51add16a5644a

[pstehlik]

cool thanks. will check it out.