Creates a new window class object. Allowed %OPTIONS
are:
-name => STRING the name for the class (it must be unique!). -icon => Win32::GUI::Icon object -cursor => Win32::GUI::Cursor object -color => COLOR or Win32::GUI::Brush object the window background color. -menu => STRING a menu name (not yet implemented). -extends => STRING name of the class to extend (aka subclassing). -widget => STRING name of a widget class to subclass; currently available are: Button, Listbox, TabStrip, RichEdit. -style => FLAGS use with caution!