Merge branch 'master' into release-0.1.3
release branch & unstable flag.
Merge branch 'release-0.1.3' into dev-0.1.3
minor: checkpoint added, protecting past transactions.
Merge branch 'dev-0.1.3' into release-0.1.3
Merge branch 'release-0.1.3'
minor: re-marking branch as stable.