Moving X11 install into their own subdirectory

[Blair Zajac]

Hello,

I haven't followed closely the work on getting X11 into the MacPorts, but I was 
installing some new ports today and the xorg-libice port conflicts with an 
existing port, ice-cpp, on the libIce.dylib.  Unfortunately, they have different 
capitalization, ice-cpp has libIce.dylib and xorg-libice has libICE.dylib.

Given precedence of an existing port and following the Linux standard, it seems 
moving the xorg-* ports into $prefix/X11 or $prefix/X11R6 would be a good thing 
to do.

Comments?

Regards,
Blair