Revert to Xinerama 1.1
In order to make a "quick" release it has been decided that the priority is to
preserve the server's internal API/ABI so that third-party drivers that depend
on symbols like noPanoramiXExtension, etc., would not need to be recompiled. Too
bad gcc on Linux doesn't support ELF's weak symbols as that would have been a
reasonable solution for preserving the ABI.