Merge pull request #477 from portertech/oj

Use Oj, a faster JSON parser
[beta] build 0.9.12.beta, updated changelog
Merge pull request #478 from portertech/beta

[beta] build 0.9.12.beta, updated changelog
[beta] need Oj compat mode, beta version bump
Merge pull request #479 from portertech/beta

[beta] need Oj compat mode, beta version bump
[beta] do not mutate previous_occurrence
[beta] new oj release, fixed rb_infinity on centos
Merge pull request #481 from portertech/beta

[beta] new oj release, fixed rb_infinity on centos
[keepalive] send ok keepalive check results, fixed history & flap detection
[keepalive] adjusted keepalive ok check output
Merge pull request #482 from portertech/keepalive

Improved stale client checking, fixed keep-alive check history & flap detection.
[beta] beta version bump
Merge pull request #483 from portertech/beta

[beta] beta version bump
[changelog] updated changelog w/ keepalive check fixes
Merge pull request #484 from portertech/changelog

[changelog] updated changelog w/ keepalive check fixes
[reconnect] improved unsubscribe & server rabbitmq connection reconnect
            - used before_reconnect queue callbacks to handle consumer clean up
Merge pull request #487 from portertech/reconnect

[reconnect] improved unsubscribe & server rabbitmq connection reconnect
[extension-stop] provide an extension stop hook, tread carefully
Merge pull request #486 from portertech/extension-stop

[extension-stop] provide an extension stop hook, tread carefully
[beta] beta version bump, updated changelog