patch 8.0.0031

Problem:    After ":bwipeout" 'fileformat' is not set to the right default.
Solution:   Get the default from 'fileformats'. (Mike Williams)

src/version.c

@@ -764,6 +764,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    31,
 /**/
     30,
 /**/