Add containers-common spec and command to podman

Since containers-common package is tied to specific versions
of Podman, add tools to build the package into the contrib directory
This should help other distributions to figure out which commont
package to ship.

Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>

vendor/github.com/containers/common/pkg/parse/parse.go

@@ -34,6 +34,10 @@ func ValidateVolumeOpts(options []string) ([]string, error) {
 			finalOpts = append(finalOpts, opt)
 			continue
 		}
+		if strings.HasPrefix(opt, "idmap") {
+			finalOpts = append(finalOpts, opt)
+			continue
+		}
 
 		switch opt {
 		case "noexec", "exec":
@@ -84,7 +88,6 @@ func ValidateVolumeOpts(options []string) ([]string, error) {
 			// are intended to be always safe to use, even not on OS
 			// X).
 			continue
-		case "idmap":
 		default:
 			return nil, errors.Errorf("invalid option type %q", opt)
 		}