Update to double-dash everywhere

These were found using `git grep -nE '[^-a-zA-Z0-9<>]-[a-zA-Z0-9]{2}'` (fair warning: _many_ false positives there).

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
Update libcontainer readme and todo list
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Merge pull request #4657 from crosbymichael/update-libcontainer-docs

Update libcontainer readme and todo list
as you could have multiple messages per line with streams, don't \r

Docker-DCO-1.1-Signed-off-by: Victor Vieux <victor.vieux@docker.com> (github: vieux)
Merge pull request #4646 from tianon/double-dash

Update to double-dash everywhere
Merge pull request #4658 from vieux/fix_display_build

fix build output