Fixed API 1.12 links and misc other fixes

Docker-DCO-1.1-Signed-off-by: James Turnbull <james@lovedthanlost.net> (github: jamtur01)
Updated Docker Hub documentation

Docker-DCO-1.1-Signed-off-by: James Turnbull <james@lovedthanlost.net> (github: jamtur01)
Merge pull request #6297 from jamtur01/hub

Updated Docker Hub documentation
Merge pull request #6299 from jamtur01/12link

Fixed API 1.12 links and misc other fixes
Update windows.md

Replace "OS X" by "Windows"
Merge pull request #6302 from Costent/patch-1

Update windows.md
Do not build using sudo on Mac OS X

Building using sudo fails on Mac OS X, but is necessary on Linux.

See https://groups.google.com/d/topic/docker-dev/1EW_pfA1t9o/discussion for discussion.

Docker-DCO-1.1-Signed-off-by: Glyn Normington <gnormington@gopivotal.com> (github: glyn)