1.4.2 Add RAID10 "far" and "offset" algorithm support.
1.5.0 Add message interface to allow manipulation of the sync_action.
New status (STATUSTYPE_INFO) fields: sync_action and mismatch_cnt.
+1.5.1 Add ability to restore transiently failed devices on resume.
+1.5.2 'mismatch_cnt' is zero unless [last_]sync_action is "check".