fix docker version git output
Packaging, issue 919: Bump version to 0.4.2
Fixed on documentation.

* replaced previously removed concepts/containers and concepts/introcution by a redirect
* moved orphan index/varable to workingwiththerepository
* added favicon to the layout.html
* added redirect_home which is a http refresh redirect. It works like a 301 for google
* fixed an issue in the layout that would make it break when on small screens
Merge pull request #920 from dotcloud/919-packaging

Packaging, issue 919: Bump version to 0.4.2
Merge pull request #914 from ToothlessGear/fix-version-output

* Client: Fix docker version's git commit output
Merge pull request #921 from dhrp/docs-redirects-and-fixes

Fixes on documentation. LGTM
Merge branch 'master' into race_attach-fix
Remove useless goroutine