Bucky

* [NEW] Add percentile thresholds config option

* [NEW] Sets
* [NEW] Delete idlestats
* [NEW] Make join timeout for subprocesses configurable
* [NEW] Sentry Support, log error message to Sentry server
* [NEW] Support for PyPy
* [NEW] Collectd to support configurable number of worker processes
* [FIX] Do not exit bucky when carbon daemon is down, instead log and drop
the message after max_reconnects and continue processing
* [FIX] Raise proper NotImplementedError
* [FIX] Don't have collectd crypto file on empty auth_file
* [FIX] Handle collectd counter/derive conflict (a little better)
* [FIX] Handle signals more gracefully
* [FIX] name_postfix_parts config option
* [FIX] Error in optparse for --collectd-types option

* [FIX] Persisting gauge-values does not work

* [NEW] Python Packaging Wheel Support

* [NEW] Processor hook, a process that recieves samples as they are parsed
by the servers and performs actions on them before handing them
over to the clients.
* [NEW] CollectDCrypto support
* [NEW] StatsD Persistent Gauges
* [NEW] Graphite added backoff_factor and backoff_max parameters
* [FIX] More/Better Python3 support
* [FIX] Gauges are constant until overwritten, and not reset at flush time
* [FIX] Make metricsd server kill its handler subprocesses
* [FIX] Fix handling of collectd counter wrapping
* [FIX] Collectd types bounds checking
* [FIX] resolve bind() endpoint in udpserver, allowing to bind to hostname or ipv6 addresses
* [FIX] handle None returned from collectd metric name converter correctly

* [NEW] Allow Bucky to drop priveleges
* [NEW] Allow Bucky to set nice level (process priority)
* [NEW] Python 3 Support
* [FIX] MetricDHandler incorrect reference to metrics
* [FIX] Multiple small speed optimalisations
* [FIX] Do not use string formatting for debug log lines, use much more efficient arguments instead