Update hack/dind to match the rest of our scripts

No functional changes here, just coding style and maintainability.

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)
Month devpts before mounting subdirs

Docker-DCO-1.1-Signed-off-by: Guillaume J. Charmes <guillaume@charmes.net> (github: creack)
Merge pull request #5565 from creack/fix_devpts

Month devpts before mounting subdirs
Merge pull request #5462 from tianon/hack-dind-style

Update hack/dind to match the rest of our scripts
runconfig: add -net container:name option

Docker-DCO-1.1-Signed-off-by: Johan Euphrosine <proppy@google.com> (github: proppy)
runconfig/parse: add test for parseNetMode

Docker-DCO-1.1-Signed-off-by: Johan Euphrosine <proppy@google.com> (github: proppy)
Update --net flags and container mode
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Setup host networking for lxc and native
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Update host networking with hostname and files
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)