Fix constructor return types and method ownership (for memory management)

Fix constructor return types and method ownership (for memory management)

	modified:   webbrowser.py
         - Add frame.get_title and frame.get_location
	modified:   webkitgtk.defs
         - WebKitGtkPage constructor should return GtkWidget*
         - WebKitGtkFrame constructor should return GObject*
         - get_page, get_title, get_location: add caller-owns-return