Avoid to use zope.testing.doctestunit as it is now deprecated.

src/z3c/form/browser/tests.py

@@ -16,12 +16,11 @@
 """
 __docformat__ = "reStructuredText"
 
-import itertools
+from doctest import DocFileSuite
 import doctest
+import itertools
 import unittest
 
-from zope.testing.doctestunit import DocFileSuite
-
 from z3c.form import testing
 from z3c.form import outputchecker
 from z3c.form.ptcompat import AVAILABLE, Z3CPT_AVAILABLE

src/z3c/form/field.txt

@@ -698,7 +698,7 @@ empty:
   >>> manager.ignoreContext = True
   >>> manager.update()
 
-  >>> from zope.testing.doctestunit import pprint
+  >>> from pprint import pprint
   >>> pprint(manager.extract())
   ({'firstName': u'Stephan', 'lastName': u'Richter'}, ())
 

src/z3c/form/form.txt

@@ -1064,7 +1064,7 @@ the dictionary:
   >>> editForm = PersonDictEditForm(None, request)
   >>> editForm.update()
 
-  >>> from zope.testing.doctestunit import pprint
+  >>> from pprint import pprint
   >>> pprint(personDict)
   {'age': 5,
    'gender': 'male',