patch 7.4.987

Problem:    Can't build with Ruby 1.9.2.
Solution:   Require Rub 2.0 for defining USE_TYPEDDATA.

src/version.c

@@ -741,6 +741,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    987,
 /**/
     986,
 /**/