This is the first of two steps to break the archive package's dependence
on utils so that archive may be moved into pkg. Also, the `Go()`
function is small, concise, and not specific to the docker internals, so
it is a good candidate for pkg.
Signed-off-by: Rafe Colton <rafael.colton@gmail.com>
1. /container/<name>/exec - Creates a new exec command instance in the daemon and container '<name>'. Returns an unique ID for each exec command.
2. /exec/<name>/start - Starts an existing exec command instance. Removes the exec command from the daemon once it completes.
Adding /exec/<name>/resize to resize tty session of an exec command.
Docker-DCO-1.1-Signed-off-by: Vishnu Kannan <vishnuk@google.com> (github: vishh)
