Update doc submodule pointer to latest wiki
Adding Metrics Ganglia and Graphite support

This commit is totally untested.  This commit also javadocs all public
methods in the MetricManager class.
Tested and tweaked Ganglia Metrics reporter

* added new Ganglia Metrics reporter configuration sanity checks
* added option to set GMetric "spoof" option
* commented body of the Graphite Metrics reporter config method until
  its implemented
* javodoc'd Ganglia configuration option constants and added their
  associated default values as constants
Cleanup imports in MetricManager and GraphDBConfig
Rename metrics.ganglia.host to .hostname

Matches storage.hostname.  There's no technical reason they have to
match, I'm just trying to stick to precedent.
Added Metrics Graphite reporter support

I just tested this against a local Graphite instance and successfully
ingested data and exercised the Graphite "prefix" config option, but I
didn't scrutinize the results beyond that.  This Graphite reporter
support should be considered lightly tested.