patch 8.0.0019

Problem:    Test_command_count is old style.
Solution:   Turn it into a new style test. (Naruhiko Nishino)
            Use more assert functions.

src/version.c

@@ -764,6 +764,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    19,
 /**/
     18,
 /**/