py3: Port more CLI tools

Bring under test

 - test/unit/cli/test_dispersion_report.py
 - test/unit/cli/test_info.py and
 - test/unit/cli/test_relinker.py

I've verified that swift-*-info (at least) behave reasonably under
py3, even swift-object-info when there's non-utf8 metadata on the
data/meta file.

Change-Id: Ifed4b8059337c395e56f5e9f8d939c34fe4ff8dd

bin/swift-object-info

@@ -14,15 +14,23 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import codecs
 import sys
 from optparse import OptionParser
 
+import six
+
 from swift.common.storage_policy import reload_storage_policies
 from swift.common.utils import set_swift_dir
 from swift.cli.info import print_obj, InfoSystemExit
 
 
 if __name__ == '__main__':
+    if not six.PY2:
+        # Make stdout able to write escaped bytes
+        sys.stdout = codecs.getwriter("utf-8")(
+            sys.stdout.detach(), errors='surrogateescape')
+
     parser = OptionParser('%prog [options] OBJECT_FILE')
     parser.add_option(
         '-n', '--no-check-etag', default=True,