Do not drop sys_boot

This fixes #2391
- 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
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
Split auth tests between unit tests and integration tests
Move iptables test to integration tests
Merge pull request #2690 from codevin/master

Improvise documentation for builder.rst / VOLUME command
path needs to be specified to 'docker build' command

current folder '.' appended as a path
Merge pull request #1 from jpetazzo/2392-add-kernel-docs

Add warning about SYS_BOOT capability with pre-3.4 kernels and pre-0.8 LXC.
port published explicitly (for docker 0.6.6)

port 5984 to couchdb needs to be published explicitly in docker version 0.6.6
Merge pull request #2712 from makinacorpus/master

Do not drop sys_boot