Renamed RemovedInDjangoXYWarnings for new roadmap.

Forwardport of ae1d663b79
from stable/1.8.x plus more.

django/forms/extras/__init__.py

@@ -1,7 +1,7 @@
 import warnings
 
 from django.forms.widgets import SelectDateWidget
-from django.utils.deprecation import RemovedInDjango21Warning
+from django.utils.deprecation import RemovedInDjango20Warning
 
 __all__ = ['SelectDateWidget']
 
@@ -9,4 +9,4 @@ __all__ = ['SelectDateWidget']
 warnings.warn(
     "django.forms.extras is deprecated. You can find "
     "SelectDateWidget in django.forms.widgets instead.",
-    RemovedInDjango21Warning, stacklevel=2)
+    RemovedInDjango20Warning, stacklevel=2)

django/forms/fields.py

@@ -29,7 +29,7 @@ from django.forms.widgets import (
 from django.utils import formats, six
 from django.utils.dateparse import parse_duration
 from django.utils.deprecation import (
-    RemovedInDjango20Warning, RenameMethodsBase,
+    RemovedInDjango110Warning, RenameMethodsBase,
 )
 from django.utils.duration import duration_string
 from django.utils.encoding import force_str, force_text, smart_text
@@ -50,7 +50,7 @@ __all__ = (
 
 class RenameFieldMethods(RenameMethodsBase):
     renamed_methods = (
-        ('_has_changed', 'has_changed', RemovedInDjango20Warning),
+        ('_has_changed', 'has_changed', RemovedInDjango110Warning),
     )
 
 
@@ -544,7 +544,7 @@ class RegexField(CharField):
             warnings.warn(
                 "The 'error_message' argument is deprecated. Use "
                 "Field.error_messages['invalid'] instead.",
-                RemovedInDjango20Warning, stacklevel=2
+                RemovedInDjango110Warning, stacklevel=2
             )
             error_messages = kwargs.get('error_messages') or {}
             error_messages['invalid'] = error_message