added testsuite for the parser

testsuite/runtime/parser/DummyNatCnc.gf

@@ -0,0 +1,8 @@
+concrete DummyNatCnc of DummyNat = {
+
+lincat Nat = Str ;
+lin zero = "z" ;
+    succ n = n ;
+    plus m n = m ++ n ;
+
+}