More parsing errors.

Invalid hash directives.
Invalid tag token.
Reserved characters.

samples/syntax_errors/08.md

@@ -0,0 +1 @@
+#include <stdio.h>

samples/syntax_errors/09.md

@@ -0,0 +1 @@
+@"tag" node

samples/syntax_errors/10.md

@@ -0,0 +1,2 @@
+#namespace foo
+{a,#b}