Steps to reproduce:
1. Launch gnome-display-properties on a machine with X Server that does not
   provide XRANDR extension (e..g Sparc machine running XSun)
2. gnome-display-properties cores.



Stack trace:
core 'core' of 19540:	gnome-display-properties
 ff2c766c _lwp_kill (6, 0, 5, 6, ffffffff, 6) + 8
 ff24f5a4 abort    (0, 1, 6, ff35ff00, 10f19c, 0) + 108
 feb54038 g_logv   (1aac8, 6, 5, 6, 4, febf6c48) + 484
 feb54064 g_log    (1aac8, 4, 1ac6c, 15400, 18b20, fa9b57b8) + 1c
 00017eb8 run_application (1a800, 1ac00, 21d0, a4850, febf6c48, 1a800) + 70
 000182c0 main     (1ac00, ffbffaf4, 1ac00, 1ac00, 1ac00, 1ac00) + 54
 00015008 _start   (0, 0, 0, 0, 0, 0) + 108

Other information:
The crash is simply occuring due to g_error() call stating "Cannot get screen info".

This is really useless information to the user. The message should be a warning
and the application should exit gracefully, and provide a much more meaningful
message. Looking at the po files there is an existing message that used to exist
for capplets/display/main.c, however main.c does not exist anymore presumably 
because of a rewrite.