This patch removes Ganglia integration from the default build. It
allows users willing to link against LGPL code to use Ganglia
by adding build flags or linking against a new Spark artifact called
spark-ganglia-lgpl.
This brings Spark in line with the Apache policy on LGPL code
enumerated here:
https://www.apache.org/legal/3party.html#options-optional
Author: Patrick Wendell <pwendell@gmail.com>
Closes#108 from pwendell/ganglia and squashes the following commits:
326712a [Patrick Wendell] Responding to review feedback
5f28ee4 [Patrick Wendell] SPARK-1167: Remove metrics-ganglia from default build due to LGPL issues.
This adds a metrics sink for graphite. The sink must
be configured with the host and port of a graphite node
and optionally may be configured with a prefix that will
be prepended to all metrics that are sent to graphite.
