2.17.3 Stuff:

- Now all GDM GUI's are run as the gdm user.  This change ensures
 that all GDM GUI's can talk to the at-spi-registryd that is
 running.  This change involved making the forked slave talk
 to the the GDM daemon so that the dialogs can be displayed.
 The response from the dialog can be returned to the slave.
 There are reports that this bug triggers GDK bug #376315 on
 Linux when a11y is turned off.  This will need to be fixed
 before the next GDM stable release.  Workaround is to turn
 on a11y until this bug is fixed.  (Leena Gunda and Srirama
 Sharma)

- gdmsetup has a new tooltip suggestion.  (Calum Benson)

- Now "Default System Session" is renamed to "Run Xclient
 script" which is more accurately what this does.  Use xterm
 as fallback instead of xsm, since xsm is not available on all
 Linux.  Now zenity pop-up message is displayed when Xclient
 script is not found.  (Brian Cameron)

- Fix for TryExec check in gdmsession to make sure that any
 arguments are not passed to g_find_program_in_path since
 this causes the function to say it is not executable.
 (Brian Cameron)

- Rename Panjabi to Punjabi.  (Brian Cameron)

- Translation updates (Josep Puigdemont i Casamaj\303\263,
 Daniel Nylander)