don't user os.Stderr in attach

Docker-DCO-1.1-Signed-off-by: Victor Vieux <victor.vieux@docker.com> (github: vieux)
move build to a job

Docker-DCO-1.1-Signed-off-by: Victor Vieux <victor.vieux@docker.com> (github: vieux)
remove useless anonymous field mentions

Docker-DCO-1.1-Signed-off-by: Victor Vieux <victor.vieux@docker.com> (github: vieux)
Fix TOC for Articles
Merge pull request #3748 from metalivedev/fixarticles

Fix TOC for Articles
Merge pull request #3726 from vieux/attach_stderr

don't user os.Stderr in attach
Merge pull request #3741 from vieux/build_job

move build to a job