Using declarations, directors and overloaded methods

Language::unrollVirtualMethods was assuming that the using
declaration would only introduce one method. Fix this by adding
in all the overloaded methods from a base class.

Affects code generation in C# and Java, but I was not able
to construct a test that failed before this commit.

Examples/test-suite/java/director_using_member_scopes_runme.java

@@ -0,0 +1,64 @@
+
+import director_using_member_scopes.*;
+
+public class director_using_member_scopes_runme {
+
+  static {
+    try {
+      System.loadLibrary("director_using_member_scopes");
+    } catch (UnsatisfiedLinkError e) {
+      System.err.println("Native code library failed to load. See the chapter on Dynamic Linking Problems in the SWIG Java documentation for help.\n" + e);
+      System.exit(1);
+    }
+  }
+
+  public static void main(String argv[]) {
+    NativeWindowType nwt = new NativeWindowType();
+
+    {
+      director_using_member_scopes_MyApplicationContextSDL a = new director_using_member_scopes_MyApplicationContextSDL();
+
+      if (ApplicationContextBase.call_setWindowGrab(a, nwt, true) != 100)
+        throw new RuntimeException("failed");
+
+      if (ApplicationContextSDL.call_setWindowGrab(a, nwt, true) != 100)
+        throw new RuntimeException("failed");
+    }
+
+    {
+      director_using_member_scopes_MyACSDL a = new director_using_member_scopes_MyACSDL();
+
+      if (ACB.call_setWindowGrab(a, nwt, true) != 100)
+        throw new RuntimeException("failed");
+      if (ACB.call_setWindowGrab(a, "hi", 0) != 200)
+        throw new RuntimeException("failed");
+
+      if (ACSDL.call_setWindowGrab(a, nwt, true) != 100)
+        throw new RuntimeException("failed");
+      if (ACSDL.call_setWindowGrab(a, "hi", 0) != 200)
+        throw new RuntimeException("failed");
+    }
+  }
+}
+
+class director_using_member_scopes_MyApplicationContextSDL extends ApplicationContextSDL {
+  @Override
+  public int setWindowGrab(NativeWindowType win, boolean grab)
+  {
+    return 100;
+  }
+}
+
+class director_using_member_scopes_MyACSDL extends ACSDL {
+  @Override
+  public int setWindowGrab(NativeWindowType win, boolean grab)
+  {
+    return 100;
+  }
+
+  @Override
+  public int setWindowGrab(String s, int val)
+  {
+    return 200;
+  }
+}