Merge branch 'master' of github.com:ucb-sts/sts into snapshot_peek
Merge branch 'master' of github.com:ucb-sts/sts into snapshot_peek
Add SnapshotPeeker, and refactor to remove redundancy. Not yet tested
Use "record only" rather than "passthrough and record"t
Fix a flaw in the protocol: need to keep true_io_worker scheduled to see
messages during peek()

Instead, clone true_io_worker's buffers, and set the simulation to
"record-only" mode, then peek(), then set true_io_worker's buffers back to
their state before snapshotting, then proceed normally.
Merge branch 'snapshot_prototype' of github.com:ucb-sts/sts into snapshot_peek
Use new Snapshotter class
Woops, fix bugs caught by unit tests
Add unit test for SnapshotPeeker, fix bugs found by unit test
Merge branch 'master' of github.com:ucb-sts/sts into snapshot_peek
Merge pull request #13 from ucb-sts/snapshot_peek

Snapshot peek