patch 8.0.0485: not all windows commands are tested

Problem:    Not all windows commands are tested.
Solution:   Add more tests for windows commands. (Dominique Pelle,
            closes #1575) Run test_autocmd separately, it interferes with
            other tests.  Fix tests that depended on side effects.
diff --git a/src/testdir/Make_all.mak b/src/testdir/Make_all.mak
index f785679..bc0eca5 100644
--- a/src/testdir/Make_all.mak
+++ b/src/testdir/Make_all.mak
@@ -137,6 +137,7 @@
 	    test_arglist.res \
 	    test_assert.res \
 	    test_autochdir.res \
+	    test_autocmd.res \
 	    test_backspace_opt.res \
 	    test_breakindent.res \
 	    test_bufwintabinfo.res \