Immutable manifest references, logging

The primary features in this preview are immutable manifest references and
context aware logging. A new README and a documentation outline are accompanied
by several stability improvements, as well.

This release is still considered alpha quality preview.

Notifications and stability improvements

This third alpha release includes support for webhook notifications. Several stability improvements are included that address common errors. A debug server with pprof and expvar can now be enabled.

The build system has been improved, as well.

This release is still considered alpha.

Bugfixes, godep and storagedriver improvements

This second alpha release provides fixes for s3 IAM role authentication in addition to some stability improvements in storage driver. This is still alpha quality software and should be run with that in mind.

Docker 1.5 Testing

This release marks the revision used for integration testing in Docker 1.5. It represents a point of relative API stability and backend layout. There may be considerable bugs and this should be used only with great care.

This is mostly being tagged for historical reference.