Change content-type for json stream to application/x-json-stream.

Docker-DCO-1.1-Signed-off-by: Jessica Frazelle <jess@docker.com> (github: jfrazelle)
Allow user to change email/passwd via login

Signed-off-by: Doug Davis <dug@us.ibm.com>
builder: Appropriately initialize the Cmd in runconfig.

Docker-DCO-1.1-Signed-off-by: Erik Hollensbe <github@hollensbe.org> (github: erikh)
builder: integration-cli test for the previous commit.

Docker-DCO-1.1-Signed-off-by: Erik Hollensbe <github@hollensbe.org> (github: erikh)
Merge pull request #8179 from erikh/parser_fix_cmd_null

Parser fix cmd null
Merge pull request #8170 from duglin/Issue7547

Allow user to change email/passwd via login - Issue 7547
Merge pull request #8101 from jfrazelle/6974-correct-ct-json-stream

Change content-type for json stream to application/x-json-stream.
Remove nameserver 127.0.0.1 line rather then dumping resolv.conf

We have a bug report complaining about docker dumping the contents of the
hosts resolv.conf if it container 127.0.0.1.  They asked that instead
of dropping the file altogether, that we just remove the line.

This patch removes the 127.0.0.1 lines, if they exist and then
checks if any nameserver lines exist.

Docker-DCO-1.1-Signed-off-by: Dan Walsh <dwalsh@redhat.com> (github: rhatdan)