Adds nfs client collector NfsCollector based on NfsdCollector
added header doc + no auto enable
removed auto-enable for mountstats collector
Merge pull request #439 from rtoma/jcol

Added header doc for jcollectd collector and disable auto-enable
Merge pull request #438 from delias-/NfsCollector

Adds nfs client collector NfsCollector based on NfsdCollector
Merge pull request #440 from rtoma/mountstat

removed auto-enable for mountstats collector
Make possible to choose which specific metrics collect from Postgresql
Merge pull request #441 from jorgebastida/feature/postgresql-metrics

Make it possible to choose which metrics are collected from Postgresql
Skip collectors and handlers with syntax errors.

As per https://github.com/BrightcoveOS/Diamond/wiki/Installation, Diamond
supports Python 2.4+, but the kafka and jcollectd collectors break
compatibility. This change handles treats syntax errors the same as import
errors so that the server can run without incompatible collectors and handlers
on systems with older versions of Python.

Caveat: this fix only works if the core server code keeps compatibility with
Python 2.4.
Merge pull request #445 from kongregate/skip-collectors-and-handlers-with-syntax-errors

Skip collectors and handlers with syntax errors.