Fixed #21651 -- Remove recapitalize.

It was not used inside Django, is not tested or documented. Consequently
remove without deprecation path.

Thanks to @vajrasky for bringing it to our attention.

django/utils/text.py

@@ -256,15 +256,6 @@ def normalize_newlines(text):
 normalize_newlines = allow_lazy(normalize_newlines, six.text_type)
 
 
-def recapitalize(text):
-    """Recapitalizes text, placing caps after end-of-sentence punctuation."""
-    text = force_text(text).lower()
-    capsRE = re.compile(r'(?:^|(?<=[\.\?\!] ))([a-z])')
-    text = capsRE.sub(lambda x: x.group(1).upper(), text)
-    return text
-recapitalize = allow_lazy(recapitalize)
-
-
 def phone2numeric(phone):
     """Converts a phone number with letters into its numeric equivalent."""
     char2number = {'a': '2', 'b': '2', 'c': '2', 'd': '3', 'e': '3', 'f': '3',