[OCaml] Runtime tests for abstract_access, abstract_typedef and some others

Add runtime tests for abstract_access, abstract_typedef,
abstract_typedef2, abstract_virtual, aggregate, cast_operator, and
constover. The aggregate and cast_operator tests are based on the
corresponding ruby tests, and the rest are based on python tests.

Examples/test-suite/ocaml/constover_runme.ml

@@ -0,0 +1,16 @@
+open Swig
+open Constover
+
+let test_str = "test" to string
+let _ =
+  assert ((_test (test_str) as string) = "test");
+  assert ((_test_pconst (test_str) as string) = "test_pconst");
+;;
+
+let f = new_Foo '()
+let _ =
+  assert ((f -> "test" (test_str) as string) = "test");
+  assert ((f -> "test_pconst" (test_str) as string) = "test_pconst");
+  assert ((f -> "test_constm" (test_str) as string) = "test_constmethod");
+  assert ((f -> "test_pconstm" (test_str) as string) = "test_pconstmethod");
+;;