gtk-logout-helper should be built unconditionally

[Charles Kerr]

indicator-session in the 12.04 and 12.10 cycles has unnecessary code for deciding when to build gtk-logout-helper. However if we want our dialogs to follow our design spec at as per https://wiki.ubuntu.com/SessionHandling, we should be buliding gtk-logout-helper and use it unconditionally in the session menu, rather than delegating work to gnome-session-exit.

[Balló György (ballogy)]

I requested this change[1], because gtk-logout-helper requires a patch for gnome-session to support RequestShutdown and RequestReboot DBus requests, which is now rejected by upstream[2]. I'm packaging indicator-session for Arch Linux, and I need to make it usable with vanilla gnome-session. ConsoleKit is no longer available in Arch Linux, so it's not an option.

The only way to shutdown/restart over DBus on Arch Linux is to use logind[3], but It isn't supported by gtk-logout-helper yet.

[1] https://code.launchpad.net/~ballogy/indicator-session/make-gtklogouthelper-and-apt-optional/+merge/83863
[2] https://bugzilla.gnome.org/show_bug.cgi?id=575880
[3] http://www.freedesktop.org/wiki/Software/systemd/logind

[Charles Kerr (charlesk)]

The logout helper is now built into indicator-session and build unconditionally, as of 12.10.5+13.10.20130716-0ubuntu1