patch 9.1.0096: diff() function uses 'diffexpr'

Problem:  diff() function uses 'diffexpr'
          (rickhowe)
Solution: Make diff() always use internal diff(), add support for
          unified diff context length, sort diff() options in help
          (Yegappan Lakshmanan)

fixes: #13989
closes: #14010

Signed-off-by: Yegappan Lakshmanan <yegappan@yahoo.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

src/version.c

@@ -704,6 +704,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    96,
 /**/
     95,
 /**/