Do not drop sys_boot

This fixes #2391
Merge pull request #2577 from dotcloud/bump_v0.6.6

Bump v0.6.6
- Fix the attach examples according to the new attach behavior
- Add the option of adding the user to docker's group and avoid the usage of "sudo" before each command
- Included the sudo alternative as an example_header
skip the volumes mounted when deleting the volumes of container.
use Binds key in hostConfig to detect volumes mounted from external.
Minor code simplification for Containers api
Add warning about SYS_BOOT capability with pre-3.4 kernels and pre-0.8 LXC.
Add more depth to the upstart example in host_integration.rst

I found that the original example wasn't starting the docker container when docker is started.  So, I modified it using information I found from https://groups.google.com/forum/#!msg/docker-user/OWz8EOpiXuo/L_uxGFQuYlkJ

Also, upstart wasn't starting docker if it wasn't running ahead of time.  So, I added a change to the docker upstart script to solve this.
Clean up sphinx syntax, upgrade http markup package, minor link changes, update intro.
Improvise documentation for builder.rst / VOLUME command
Move integration tests to integration/, expose missing public methods in the core
Integration tests: remove dependency on private APIs
gofmt
Remove deprecated tags_test.go
fix Integration tests
move TestMount to integration
Fix the brittle errorstring-to-httperror recognition code which in turn is required by autopull (the client issues a pull if container creation returns 404)
Merge pull request #2704 from shykes/fix-auto-pull

Fix the brittle errorstring-to-httperror recognition code
Split auth tests between unit tests and integration tests