display: Add convenient shorthand for win.request_properties()

Now instead of this:

    win.request_properties(WindowProperties(title="Test"))

You can directly do this:

    win.request_properties(title="Test")

panda/src/display/graphicsWindow.h

@@ -55,7 +55,9 @@ PUBLISHED:
   const WindowProperties get_requested_properties() const;
   void clear_rejected_properties();
   WindowProperties get_rejected_properties() const;
-  void request_properties(const WindowProperties &requested_properties);
+
+  EXTENSION(void request_properties(PyObject *args, PyObject *kwds));
+
   INLINE bool is_closed() const;
   virtual bool is_active() const;
   INLINE bool is_fullscreen() const;
@@ -100,6 +102,8 @@ PUBLISHED:
   virtual void close_ime();
 
 public:
+  void request_properties(const WindowProperties &requested_properties);
+
   virtual void add_window_proc( const GraphicsWindowProc* wnd_proc_object ){};
   virtual void remove_window_proc( const GraphicsWindowProc* wnd_proc_object ){};
   virtual void clear_window_procs(){};

panda/src/display/graphicsWindow_ext.cxx

@@ -12,9 +12,26 @@
  */
 
 #include "graphicsWindow_ext.h"
+#include "windowProperties_ext.h"
 
 #ifdef HAVE_PYTHON
 
+/**
+ * Convenient shorthand for requesting properties.
+ */
+void Extension<GraphicsWindow>::
+request_properties(PyObject *args, PyObject *kwds) {
+  extern struct Dtool_PyTypedObject Dtool_WindowProperties;
+
+  WindowProperties props;
+  PyObject *py_props = DTool_CreatePyInstance((void *)&props, Dtool_WindowProperties, false, false);
+
+  invoke_extension(&props).__init__(py_props, args, kwds);
+
+  _this->request_properties(props);
+  Py_DECREF(py_props);
+}
+
 /**
  * Adds a python event handler to be called when a window event occurs.
  */

panda/src/display/graphicsWindow_ext.h

@@ -30,6 +30,8 @@
 template<>
 class Extension<GraphicsWindow> : public ExtensionBase<GraphicsWindow> {
 public:
+  void request_properties(PyObject *args, PyObject *kwds);
+
   void add_python_event_handler(PyObject* handler, PyObject* name);
   void remove_python_event_handler(PyObject* name);
 };