Nd-service-registry

* 20: Fix Registration.update() method - check that type(state) is bool.

* Quiet down the Kazoo logger

* 18: Fix bogus log.debug() statement that caused KeyError exception.
* 19: Make sure we call set_state any time *state* is a boolean.

* Bugfix: If kazoo.Semaophore() is in canceled state, retry the lock.
* Bugfix: release_lock() was calling _get_lock() with missing parameters
* Bugfix: Cancel a pending lock when Lock.release() is called
* 17: Replace time.sleep() with client.handler.sleep_func()
* 16: Add *wait=X* option to Lock objects

* Misc documentation cleanup
* Added Gerrit code review docs and hooks
* Explicitly filter out Kazoo *PING* messages with a Logging Filter
* Moved *Fork Detected* messages to logging.INFO
* 13: Use package-level logging objects rather than class-level
* 12: Support for Kazoo 1.0b1 enhancement
* 11: Implement a Lock handler model enhancement
* 10: Zookeeper API throttling should be configurable
* 9: Exception NoNodeError can be thrown when re-connecting to Zookeeper after connection loss

* Quiet down *shutdown* function
* Clean up the logging object names
* 8: Fix funcs.save_dict() when permissions are incorrect
* 6: Fix *on fork* behavior