old_contents: try:
      from json_field.fields import JSONField
  except ImportError:
      pass # fails when imported by setup.py, no worries
  
  __version__ = '0.4.2'
  
new_contents: from django.core.exceptions import ImproperlyConfigured
  try:
      from json_field.fields import JSONField
  except (ImportError, ImproperlyConfigured):
      pass # fails when imported by setup.py, no worries
  
  __version__ = '0.4.2'
  
subject: Fix install with Django 1.5.