patch 8.0.1224: still interference between test functions

Problem:    Still interference between test functions.
Solution:   Clear autocommands. Wipe all buffers.  Fix tests that depend on a
            specific start context.

src/version.c

@@ -761,6 +761,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1224,
 /**/
     1223,
 /**/