Don't fail to start if Xinerama isn't available
Don't fail to start if Xinerama isn't available

If the Xinerama module was used when Xinerama wasn't available then it prevented Ion from starting correctly.
This is a problem for e.g. a laptop which sometimes has an external monitor attached. With this patch, Ion still starts correctly.

darcs-hash:20070719165604-072e0-17e1a0cebad1c70d52c517ca8ebceda55b72f12c.gz

dkogan/notion.xfttest,knixeur/notion,p5n/notion,dkogan/notion,dkogan/notion,knixeur/notion,p5n/notion,neg-serg/notion,anoduck/notion,knixeur/notion,dkogan/notion.xfttest,raboof/notion,p5n/notion,p5n/notion,knixeur/notion,raboof/notion,raboof/notion,dkogan/notion,dkogan/notion.xfttest,knixeur/notion,anoduck/notion,dkogan/notion,neg-serg/notion,p5n/notion,anoduck/notion,dkogan/notion,neg-serg/notion,dkogan/notion.xfttest,anoduck/notion,anoduck/notion,neg-serg/notion,raboof/notion