Remove unused openstack.common.importutils

When the code in openstack.common.log was updated, it is now consuming the
importutils from oslo.utils. There are no longer local references to this
code.

Change-Id: I09ff72e307c1d5ee58388184a97a36ae183d7b0e
Partially-Implements: blueprint improve-oslo-usage

openstack-common.conf

@@ -1,7 +1,6 @@
 [DEFAULT]
 module=_i18n
 module=fileutils
-module=importutils
 module=install_venv
 module=local
 module=log

openstack_dashboard/openstack/common/importutils.py

@@ -1,73 +0,0 @@
-# Copyright 2011 OpenStack Foundation.
-# All Rights Reserved.
-#
-#    Licensed under the Apache License, Version 2.0 (the "License"); you may
-#    not use this file except in compliance with the License. You may obtain
-#    a copy of the License at
-#
-#         http://www.apache.org/licenses/LICENSE-2.0
-#
-#    Unless required by applicable law or agreed to in writing, software
-#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
-#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
-#    License for the specific language governing permissions and limitations
-#    under the License.
-
-"""
-Import related utilities and helper functions.
-"""
-
-import sys
-import traceback
-
-
-def import_class(import_str):
-    """Returns a class from a string including module and class."""
-    mod_str, _sep, class_str = import_str.rpartition('.')
-    try:
-        __import__(mod_str)
-        return getattr(sys.modules[mod_str], class_str)
-    except (ValueError, AttributeError):
-        raise ImportError('Class %s cannot be found (%s)' %
-                          (class_str,
-                           traceback.format_exception(*sys.exc_info())))
-
-
-def import_object(import_str, *args, **kwargs):
-    """Import a class and return an instance of it."""
-    return import_class(import_str)(*args, **kwargs)
-
-
-def import_object_ns(name_space, import_str, *args, **kwargs):
-    """Tries to import object from default namespace.
-
-    Imports a class and return an instance of it, first by trying
-    to find the class in a default namespace, then failing back to
-    a full path if not found in the default namespace.
-    """
-    import_value = "%s.%s" % (name_space, import_str)
-    try:
-        return import_class(import_value)(*args, **kwargs)
-    except ImportError:
-        return import_class(import_str)(*args, **kwargs)
-
-
-def import_module(import_str):
-    """Import a module."""
-    __import__(import_str)
-    return sys.modules[import_str]
-
-
-def import_versioned_module(version, submodule=None):
-    module = 'openstack_dashboard.v%s' % version
-    if submodule:
-        module = '.'.join((module, submodule))
-    return import_module(module)
-
-
-def try_import(import_str, default=None):
-    """Try to import a module and if it fails return default."""
-    try:
-        return import_module(import_str)
-    except ImportError:
-        return default