patch 7.4.1892

Problem:    balloon eval only gets the window number, not the ID.
Solution:   Add v:beval_winid.

src/version.c

@@ -753,6 +753,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1892,
 /**/
     1891,
 /**/