patch 8.1.0658: deleting signs and completion for :sign is insufficient

Problem:    Deleting signs and completion for :sign is insufficient.
Solution:   Add deleting signs in a specified or any group from the current
            cursor location.  Add group and priority to sign command
            completion. Add tests for different sign unplace commands. Update
            help text.  Add tests for sign jump with group. Update help for
            sign jump. (Yegappan Lakshmanan, closes #3731)
diff --git a/src/netbeans.c b/src/netbeans.c
index 9b6b522..c8084df 100644
--- a/src/netbeans.c
+++ b/src/netbeans.c
@@ -1251,12 +1251,12 @@
 		    /* delete signs from the lines being deleted */
 		    for (i = del_from_lnum; i <= del_to_lnum; i++)
 		    {
-			int id = buf_findsign_id(buf->bufp, (linenr_T)i);
+			int id = buf_findsign_id(buf->bufp, (linenr_T)i, NULL);
 			if (id > 0)
 			{
 			    nbdebug(("    Deleting sign %d on line %d\n",
 								      id, i));
-			    buf_delsign(buf->bufp, id, NULL);
+			    buf_delsign(buf->bufp, 0, id, NULL);
 			}
 			else
 			{