Remove unused stuff

[Marco Giusti]

There is a lot of stuff that is not implemented and the code raise
explicitly the NotImplmenetedError exception. That code and the relative
gui should be remove to slim the code. As the code is versioned it is
always possible to recover it in the future.

Here some things are not used in the glade project:

- dialog_bookmarks
- dialog_confirm (not used anymore)
- dialog_confirm_action
- dialog_jobmonitor
- dialog_new_redirect
- dialog_newnetcard
- dialog_usbdev
- menu_popup_bookmarks
- menu_popup_imagelist
- menu_popup_usbguest
- menu_popup_usbhost
- menu_popup_volumes
- window_userwait

[Marco Giusti (marco-giusti)]

Here some other stuff not used:

- ifconfig_win
- topology_export_dialog
- autoshow/autohide menus

[Marco Giusti (marco-giusti)]

Fixed in one of various commits.