Get an extra pair of eyes on the Softlayer installation docs

Docker-DCO-1.1-Signed-off-by: SvenDowideit <SvenDowideit@home.org.au> (github: SvenDowideit)
Updating to reflect changes in the SoftLayer portal and product naming conventions.

Docker-DCO-1.1-Signed-off-by: Phil Jackson <underscorephil@gmail.com> (github: underscorephil)
Removed docker_io_oauth_api.md: Docker is not currently accepting registrations for third party auth while it's determined how this will be done, if at all, in the future.

Docker-DCO-1.1-Signed-off-by: hollietealok <hollie@docker.com> (github: hollietealok)
Added proposed Docker Community Guidelines

Docker-DCO-1.1-Signed-off-by: James Turnbull <james@lovedthanlost.net> (github: jamtur01)
Merge remote-tracking branch 'upstream/master' into doc_remove

Docker-DCO-1.1-Signed-off-by: hollietealok <hollie@docker.com> (github: hollietealok)
Make sure err never gets masked

Defining err as named return parameter will make sure the variable gets
assigned before returning and thus avoid masking

Docker-DCO-1.1-Signed-off-by: Johannes 'fish' Ziemke <github@freigeist.org> (github: discordianfish)
Clean up the docker socket on termination of the daemon.

Docker-DCO-1.1-Signed-off-by: Erik Hollensbe <github@hollensbe.org> (github: erikh)
Adding the query parameters to insert api call for all <= 1.10 and
removing the insert documentation for > 1.10 since it has been removed
in 1.11. This commit fixes #7183
Docker-DCO-1.1-Signed-off-by: Julien Bordellier <me@julienbordellier.com> (github: jstoja)
Update HTTP Proxy Section

Docker.service file location was missing the /usr dir.
Update nodejs_web_app.md

The image centos:centos6.4 doesn't exist. Instead you have to choose between the official centos6 or centos7. Both images does not work together with de yum npm install. When choosing an centos6.5 from another distributor (tutum) it works.
Correct Typo In Documentation
Standardize "apt-get install" usage across the repo

I might have missed some, but I think this is most of the offenders.

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
fix docker integration-cli restart test race

Docker-DCO-1.1-Signed-off-by: Erik Hollensbe <github@hollensbe.org> (github: erikh)
Merge pull request #7280 from knappe/patch-1

Correct Typo In Documentation
integcli: add some more docker utils

Docker-DCO-1.1-Signed-off-by: Cristian Staretu <cristian.staretu@gmail.com> (github: unclejack)
integcli: use dockerCmdInDir in build tests

Docker-DCO-1.1-Signed-off-by: Cristian Staretu <cristian.staretu@gmail.com> (github: unclejack)
move resumablerequestreader to pkg

Docker-DCO-1.1-Signed-off-by: Cristian Staretu <cristian.staretu@gmail.com> (github: unclejack)
Merge pull request #7269 from r0n22/patch-1

Update HTTP Proxy Section
Merge pull request #7256 from jstoja/docs-api-insert-image

Fixing docs - Insert api call
Merge pull request #6877 from underscorephil/patch-1

Update softlayer.md