pgk: [breeze-queue] update to 0.3.x
cache: store settings on self
codecs: [gateway.response] add gateway response codec
test: [cache] increase test delays for more leighway
errors: add GatewayNotificationError for apn response errors
code: [gateway response] change status to code.
message: [device] if no args, return device
test: [cache] increase fuzziness of timing
agent: [all] implement cache mechanism

cache mechanism facilitates retrying messages that
occur after apple sends an error and disconnects

- implement cache
- upgrade queue to breeze-queue@0.3.0
- queueIterate is not _queueIterator (suggested private)
- clean up connect callback hierarchy
examples: [error.mitigation] refactor to handle different situations