patch 7.4.1988

Problem:    When updating viminfo with file marks there is no time order.
Solution:   Remember the time when a buffer was last used, store marks for
            the most recently used buffers.

src/version.c

@@ -758,6 +758,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1988,
 /**/
     1987,
 /**/