[Bug 36523] expose nodisplay options in python

[Travis Watkins]

Public bug reported:
https://launchpad.net/malone/bugs/36523

Affects: gnome-menus (Ubuntu)
       Severity: Normal
       Priority: (none set)
         Status: Unconfirmed

Description:
This patch exposes the is_nodisplay() method and FLAGS_INCLUDE_NODISPLAY
flag in the python bindings. This is needed for alacarte to use gmenu.