This seems to have been confusing people, using both xlibs and xorg, etc. - Avoided renaming local (and different) xlibs binding in gcc*. - Fixed cases where both xorg and xlibs were used. Hopefully everything still works as before.
Scilab note: the parameters already had pointed to nonexistent dirs before this set of refactoring. But that config wasn't even used by default.
Patch by John Altobelli <acocaracha@gmail.com>, minor edits by Ludovic Courtès <ludo@gnu.org>. svn path=/nixpkgs/trunk/; revision=13823
