add syntax cIncludeDir "$projpath/include"; do not use recursive search paths; add test tests/tnimterop_cpp.nim

tests/include/test2.cpp

@@ -0,0 +1,8 @@
+#include "test2.hpp"
+
+// BUG: should complain
+// # include test2.h
+
+int test_call_int() {
+  return 5; 
+}

tests/include/test2.hpp

@@ -0,0 +1,20 @@
+#define TEST_INT 512
+
+int test_call_int();
+
+struct Foo{
+  int bar;
+};
+
+class Foo1{
+  int bar1;
+};
+
+template<typename T>
+struct Foo2{
+  int bar2;
+};
+
+typedef Foo2<int> Foo2_int;
+
+