[Bug 36523] make gmenu usable for alacarte

[Travis Watkins]

Public bug report changed:
https://launchpad.net/malone/bugs/36523

Summary changed to:
    make gmenu usable for alacarte
Description changed to:
    This patch adds gmenu_tree_entry_get_terminal() with python binding
    and exposes the is_nodisplay() method and FLAGS_INCLUDE_NODISPLAY
    flag in the python bindings. This is needed for alacarte to use
    gmenu.