reworking out of date error to instance status update error
fixing ballot failure retries type
switching preaccept to use InvalidStatusUpdateError
switching accept to use InvalidStatusUpdateError
switching commit to use InvalidStatusUpdateError
starting work converting accept tests to gocheck
converting accept tests to gocheck
adding commit stats
adding common support for mocking prepare methods, and a replica test
adding commit grace period logic to the prepare phase method
imlplementing tests around preaccept phase wait/timeout logic
implementing tests around prepare phase 2 phase selection logic
adding ballot update and test, fixing a preaccept prepare test to hit accept
fixing typo
skipping rejected instances in apply, and adding test
adding test around dependency chain execution skipping rejected instances
adding code to recalculate the exOrder and uncommitted instances after a prepare phase
replacing rejected status with instance noop flag, and updating rejected tests
adding noop to instance copy
adding noop tests