'podman port' doesn't work correctly when passed a port number

[KurtGaastra]

Is this a BUG REPORT or FEATURE REQUEST? (leave only one on its own line)

/kind bug

Description
podman port doesn't work correctly when passed a port number.

There are a few problems.

1. If the container has multiple ports published then only the first one is matched. See the early return on cmd/podman/port.go:Line 131

2. When you specify a container by name it doesn't work at all.
   In cmd/podman/port.go, func portCmd(c *cliconfig.PortValues)
   c.InputArgs is handled correctly, and the container name and port are correctly extracted
   Line 100: c is then passed to runtime.Port(c) where c.InputArgs gets treated as a list of container names

3. (Minor) One of the resulting error messages is incomplete because it uses an unassigned variable containerName

Steps to reproduce the issue:

1. podman run --rm -d -p 9999:5432 -p 9998:5433 postgres

2. podman port --latest 5432

Describe the results you received:

Error: No public port '5432' published for

Describe the results you expected:

0.0.0.0:9999
0.0.0.0:9998

Steps to reproduce the issue:

1. podman run -d --name port_test -p 9999:5432 postgres

2. podman port port_test 5432

Describe the results you received:
No output on version 1.4.4
When built from master the error message
Error: no container with name or ID 5432 found: no such container

Describe the results you expected:
0.0.0.0:9999

Output of podman version:

Version:            1.4.4
RemoteAPI Version:  1
Go Version:         go1.10.4
OS/Arch:            linux/amd64

Also tested against build from master.

[mheon]

@baude If you haven't started on this, I can take it.