Remove #noqa from most common imports and add them to import_exceptions

We have a lot of import with #noqa that is there to ignore h302,
because it's traditional to import and use a name directly, instead
of a whole module. This hides other errors and gives people the
impression that it's actually fine to import non-modules, you just
have to slap #noqa on those lines.

I went through the code and identified about a dozen names that are
most commonly imported this way. I remove the #noqa tag from them,
and added them to the list in import_exceptions.

I also removed a few unused imports that were revealed in the process.

Change-Id: I27afb8e2b1d4759ec974ded9464d8f010312ee78

openstack_dashboard/api/heat.py

@@ -14,7 +14,7 @@
 
 import logging
 
-from django.conf import settings  # noqa
+from django.conf import settings
 from heatclient import client as heat_client
 from openstack_dashboard.api import base
 

openstack_dashboard/dashboards/project/stacks/forms.py

@@ -16,7 +16,7 @@ import json
 import logging
 import re
 
-from django.utils.translation import ugettext_lazy as _  # noqa
+from django.utils.translation import ugettext_lazy as _
 from django.views.decorators.debug import sensitive_variables  # noqa
 
 from horizon import exceptions

openstack_dashboard/dashboards/project/stacks/mappings.py

@@ -17,7 +17,7 @@ import logging
 import re
 import urlparse
 
-from django.core.urlresolvers import reverse  # noqa
+from django.core.urlresolvers import reverse
 from django.template.defaultfilters import register  # noqa
 
 from openstack_dashboard.api import swift

openstack_dashboard/dashboards/project/stacks/panel.py

@@ -12,7 +12,7 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
-from django.utils.translation import ugettext_lazy as _  # noqa
+from django.utils.translation import ugettext_lazy as _
 
 import horizon
 

openstack_dashboard/dashboards/project/stacks/tables.py

@@ -15,7 +15,7 @@
 from django.http import Http404  # noqa
 from django.template.defaultfilters import timesince  # noqa
 from django.template.defaultfilters import title  # noqa
-from django.utils.translation import ugettext_lazy as _  # noqa
+from django.utils.translation import ugettext_lazy as _
 
 from horizon import messages
 from horizon import tables

openstack_dashboard/dashboards/project/stacks/tabs.py

@@ -14,7 +14,7 @@
 
 import logging
 
-from django.utils.translation import ugettext_lazy as _  # noqa
+from django.utils.translation import ugettext_lazy as _
 
 from horizon import messages
 from horizon import tabs

openstack_dashboard/dashboards/project/stacks/tests.py

@@ -14,7 +14,7 @@
 
 import json
 
-from django.core.urlresolvers import reverse  # noqa
+from django.core.urlresolvers import reverse
 from django import http
 
 from mox import IsA  # noqa

openstack_dashboard/dashboards/project/stacks/views.py

@@ -21,10 +21,10 @@ from horizon import tables
 from horizon import tabs
 from horizon.utils import memoized
 
-from django.core.urlresolvers import reverse  # noqa
-from django.core.urlresolvers import reverse_lazy  # noqa
+from django.core.urlresolvers import reverse
+from django.core.urlresolvers import reverse_lazy
 from django.http import HttpResponse  # noqa
-from django.utils.translation import ugettext_lazy as _  # noqa
+from django.utils.translation import ugettext_lazy as _
 from django.views import generic
 
 from openstack_dashboard import api

openstack_dashboard/test/helpers.py

@@ -21,7 +21,7 @@
 from functools import wraps  # noqa
 import os
 
-from django.conf import settings  # noqa
+from django.conf import settings
 from django.contrib.auth.middleware import AuthenticationMiddleware  # noqa
 from django.contrib.messages.storage import default_storage  # noqa
 from django.core.handlers import wsgi

tox.ini

@@ -42,3 +42,21 @@ exclude =  .venv,.git,.tox,dist,doc,*openstack/common*,*lib/python*,*egg,build,p
 # H702 Formatting operation should be outside of localization method call
 # H803 git commit title should not end with period (disabled on purpose, see bug #1236621)
 ignore = E127,E128,H701,H702,H803
+
+[hacking]
+import_exceptions = collections.defaultdict,
+                    django.conf.settings,
+                    django.core.urlresolvers.reverse,
+                    django.core.urlresolvers.reverse_lazy,
+                    django.template.loader.render_to_string,
+                    django.utils.datastructures.SortedDict,
+                    django.utils.encoding.force_unicode,
+                    django.utils.html.conditional_escape,
+                    django.utils.html.escape,
+                    django.utils.http.urlencode,
+                    django.utils.safestring.mark_safe,
+                    django.utils.translation.pgettext_lazy,
+                    django.utils.translation.ugettext_lazy,
+                    django.utils.translation.ungettext_lazy,
+                    operator.attrgetter,
+                    StringIO.StringIO