[patch] Added error management in configuration backends

Hello,

        This patch basically adds exceptions in the GConf configuration
backend, if something fails. 

         It's in mlview--main-happypeng--0.9--patch-4 (archive at
http://arch.duckcorp.org/happypeng/2005-mlview), applies to 
mlview--main--0.9--patch-12 ; you can do cherrypicking with this
patch.

Cheers again,

Nicolas Centa