KAZOO-543: retry init steps if errors while loading agents/queues

KAZOO-543: publish presence updates via the gen_listener

KAZOO-714: endpoints come built

KAZOO-714: formatting, and set endpoint id on built endpoint json

KAZOO-543: fix typo

KAZOO-714: formatting and handle basic.cancel_ok

KAZOO-714: formatting updates

KAZOO-714: formatting

KAZOO-543: don't send presence update if unknown agent

KAZOO-543: update handling of queue presence

KAZOO-543: formatting update

KAZOO-657: add restart commands for agents/accts

KAZOO-657: agent maintenance methods