Test Mtgraphite emitter with new logmet endpoints

[nadgowdas]

Description

As reported by @fabolive (https://github.ibm.com/watson-foundation-services/tracker/issues/9375#issuecomment-3496780), mtgraphite emitter works with legacy endpoints and does not work with new endpoints.

Need to test and fix emitter.

[nadgowdas]

I tried publishing metrics to the new logmet endpoint. I used metrics.stage1.ng.bluemix.net. Although, in crawler log it shows it has successfully

2017-09-26 13:46:26,000 MainProcess INFO     Sent authentication with mtgraphite, returned length = 52
2017-09-26 13:46:26,262 MainProcess INFO     MTGraphite authentication server response of 1A
2017-09-26 13:46:26,364 MainProcess INFO     Confirmed write to mtgraphite socket.

on grafana, it does not show any data.

Another point, although crawler is started with frequency=60, i see only one emit log in the crawler o/p. It does not send logs periodically.

@fabolive @sahilsuneja1 @canturkisci

[fabolive]

@nadgowdas It seems to me that the new Logmet endpoints now can send "partial ACKs", that is, a message that contains fewer than the 6 bytes that comprise a full ACK. The behavior we are seeing in the mtgraphite emitter seems to be related to this change.
For our reference, here is a pull request made against a nodeJS Logmet client I maintain to support the new endpoints: IBM/logmet-client-njs#2

cc: @canturkisci @sahilsuneja1