title: django unable to start runserver
body: <p>unable to start C:\Python27\mysastha>python manage.py runserver
      c:\python27\lib\site-packages\djangotoolbox-1.6.2-py2.7.egg\djangotoolbox\db\uti
      ls.py:5: RemovedInDjango19Warning: django.utils.unittest will be removed in Djan
      go 1.9.
        from django.utils.unittest import skip</p>
  
  <pre><code>Traceback (most recent call last):
    File "manage.py", line 17, in &lt;module&gt;
      execute_from_command_line(sys.argv)
    File "c:\python27\lib\site-packages\django-1.8-py2.7.egg\django\core\managemen
  t\__init__.py", line 330, in execute_from_command_line
      utility.execute()
    File "c:\python27\lib\site-packages\django-1.8-py2.7.egg\django\core\managemen
  t\__init__.py", line 304, in execute
      django.setup()
    File "c:\python27\lib\site-packages\django-1.8-py2.7.egg\django\__init__.py",
  line 21, in setup
      apps.populate(settings.INSTALLED_APPS)
    File "c:\python27\lib\site-packages\django-1.8-py2.7.egg\django\apps\registry.
  py", line 108, in populate
      app_config.import_models(all_models)
    File "c:\python27\lib\site-packages\django-1.8-py2.7.egg\django\apps\config.py
  ", line 197, in import_models
      self.models_module = import_module(models_module_name)
    File "c:\python27\lib\importlib\__init__.py", line 37, in import_module
      __import__(name)
    File "c:\python27\lib\site-packages\django-1.8-py2.7.egg\django\contrib\auth\m
  odels.py", line 40, in &lt;module&gt;
      class Permission(models.Model):
    File "c:\python27\lib\site-packages\django-1.8-py2.7.egg\django\db\models\base
  .py", line 127, in __new__
      new_class.add_to_class('_meta', Options(meta, **kwargs))
    File "c:\python27\lib\site-packages\django-1.8-py2.7.egg\django\db\models\base
  .py", line 303, in add_to_class
      value.contribute_to_class(cls, name)
    File "c:\python27\lib\site-packages\django-1.8-py2.7.egg\django\db\models\opti
  ons.py", line 166, in contribute_to_class
      self.db_table = truncate_name(self.db_table, connection.ops.max_name_length(
  ))
    File "c:\python27\lib\site-packages\django-1.8-py2.7.egg\django\db\__init__.py
  ", line 36, in __getattr__
      return getattr(connections[DEFAULT_DB_ALIAS], item)
    File "c:\python27\lib\site-packages\django-1.8-py2.7.egg\django\db\utils.py",
  line 238, in __getitem__
      backend = load_backend(db['ENGINE'])
    File "c:\python27\lib\site-packages\django-1.8-py2.7.egg\django\db\utils.py",
  line 127, in load_backend
      raise ImproperlyConfigured(error_msg)
  django.core.exceptions.ImproperlyConfigured: 'django_mongodb_engine' isn't an av
  ailable database backend.
  Try using 'django.db.backends.XXX', where XXX is one of:
      u'django_mongodb_engine', u'mysql', u'oracle', u'postgresql_psycopg2', u'sql
  ite3'
  Error was: cannot import name decimal_to_string
  </code></pre>