Add simple std::set<> typemaps too

This is similar to the previous commit for std::map<>.

Examples/test-suite/c/li_std_set_runme.c

@@ -0,0 +1,33 @@
+#include "li_std_set/li_std_set_wrap.h"
+#include <assert.h>
+
+int main() {
+    {
+        IntSet* is = IntSet_new();
+
+        IntSet_add(is, 1);
+        IntSet_add(is, 4);
+        IntSet_add(is, 9);
+
+        assert( IntSet_size(is) == 3 );
+        assert( IntSet_has(is, 4) );
+        assert( !IntSet_has(is, 16) );
+
+        IntSet_delete(is);
+    }
+
+    {
+        StringSet* ss = StringSet_new();
+
+        StringSet_add(ss, "foo");
+        StringSet_add(ss, "bar");
+
+        assert( StringSet_size(ss) == 2 );
+        assert( StringSet_has(ss, "bar") );
+        assert( !StringSet_has(ss, "baz") );
+
+        StringSet_delete(ss);
+    }
+
+    return 0;
+}

Examples/test-suite/li_std_set.i

@@ -22,7 +22,7 @@
     %template(set_int) std::multiset<int>;
     %template(v_int) std::vector<int>;
     %template(set_string) std::set<std::string>;
-#elif defined(SWIGJAVA) || defined(SWIGCSHARP)
+#elif defined(SWIGC) || defined(SWIGJAVA) || defined(SWIGCSHARP)
     // This operator is only defined because it's needed to store objects of
     // type Foo in std::set in C++, we don't need to wrap it.
     %ignore operator<;