Ensure libpod/define does not include libpod/image

The define package under Libpod is intended to be an extremely
minimal package, including constants and very little else.
However, as a result of some legacy code, it was dragging in all
of libpod/image (and, less significantly, the util package).
Fortunately, this was just to ensure that error constants were
not duplicating, and there's nothing preventing us from
importing in the other direction and keeping libpod/define free
of dependencies.

Signed-off-by: Matthew Heon <matthew.heon@pm.me>

utils/utils.go

@@ -9,6 +9,7 @@ import (
 	"strconv"
 	"strings"
 
+	"github.com/containers/podman/v2/libpod/define"
 	"github.com/containers/storage/pkg/archive"
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
@@ -51,7 +52,7 @@ func ExecCmdWithStdStreams(stdin io.Reader, stdout, stderr io.Writer, env []stri
 
 // ErrDetach is an error indicating that the user manually detached from the
 // container.
-var ErrDetach = errors.New("detached from container")
+var ErrDetach = define.ErrDetach
 
 // CopyDetachable is similar to io.Copy but support a detach key sequence to break out.
 func CopyDetachable(dst io.Writer, src io.Reader, keys []byte) (written int64, err error) {