patch 8.1.2066: no tests for state()

Problem:    No tests for state().
Solution:   Add tests.  Clean up some feature checks.  Make "a" flag work.
diff --git a/src/version.c b/src/version.c
index 576ac23..2b2474f 100644
--- a/src/version.c
+++ b/src/version.c
@@ -758,6 +758,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2066,
+/**/
     2065,
 /**/
     2064,