patch 7.4.960

Problem:    Detecting every version of nmake is clumsy.
Solution:   Use a tiny C program to get the version of _MSC_VER. (Ken Takata)

src/version.c

@@ -741,6 +741,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    960,
 /**/
     959,
 /**/