Support for Xlibre

[leigh123linux]

@opisalwaysafag

as it needs to be re-built against the 28 ABI.
Was anyone able to successfully run this X11 fork on an NVIDIA GPU

X11Libre needs to use the same ABI that Xorg uses as I doubt nvidia will add support for it.

Maybe try

Section "ServerFlags"
    Option         "IgnoreABI" "True"
EndSection