2.2

pt-sift-fails-when-fetching-missing-tools-lp1457573

pt-osc-sleep-option-lp1413140

pt-osc-readkeymini-causes-session-lock-lp1450499

pt-mysql-summary-ask-pass-option-lp1455486

pt-archiver-purge-no-delete-mutual-exclusion-lp1452914

pt-archiver-lag-check-optimization-lp1056507

pt-archiver-doc-change-1443763

devel