A menu namespace?

Adam is of the opinion we should have a separate namespace for menu 
widgets, I am of the opinion it is not needed.

xwt.lib.menu.*
xwt.widget.menu.*

In my opinion, there are only the following relevant menu widgets:
menu (the menu toolbar)
menuitem
submenu
separator

They way I've done it, they don't overlap on anything.  The separator is 
actually fairly generic - if you look closely at some monopoly 
dialogues, the separator is the same as in a menu.

- Charlie