patch 8.0.0661: recognizing urxvt mouse codes does not work well

Problem:    Recognizing urxvt mouse codes does not work well.
Solution:   Recognize "Esc[*M" and "Esc[*m". (Maurice Bos, closes #1486)
diff --git a/src/version.c b/src/version.c
index 877a1c5..228525c 100644
--- a/src/version.c
+++ b/src/version.c
@@ -765,6 +765,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    661,
+/**/
     660,
 /**/
     659,