patch 8.0.0687: minor issues related to quickfix

Problem:    Minor issues related to quickfix.
Solution:   Set the proper return status for all cases in setqflist() and at
            test cases for this.  Move the "adding" flag outside of
            FEAT_WINDOWS. Minor update to the setqflist() help text. (Yegappan
            Lakshmanan)
diff --git a/src/version.c b/src/version.c
index e659f8c..9f2515d 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    687,
+/**/
     686,
 /**/
     685,