patch 7.4.1073

Problem:    Alloc_id depends on numbers, may use the same one twice.  It's not
            clear from the number what it's for.
Solution:   Use an enum.  Add a function to lookup the enum value from the
            name.

src/version.c

@@ -741,6 +741,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1073,
 /**/
     1072,
 /**/