Setting wxGTK to use the old gtk libs. Until wxGTK 2.8.11 they will not fix a symbol clash with glib 2.21. So we keep with glib 2.20. I also changed the default wxGTK from 2.6 to 2.8, caring so no hash is changed due to this change. Some packages using 2.6 may well build with 2.8, so we can try updating them for another commit.
Setting wxGTK to use the old gtk libs. Until wxGTK 2.8.11 they will not fix
a symbol clash with glib 2.21. So we keep with glib 2.20.
I also changed the default wxGTK from 2.6 to 2.8, caring so no hash is changed due to
this change. Some packages using 2.6 may well build with 2.8, so we can try updating
them for another commit.

svn path=/nixpkgs/trunk/; revision=18133

SymbiFlow/nixpkgs,triton/triton,NixOS/nixpkgs,triton/triton,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,triton/triton,SymbiFlow/nixpkgs,SymbiFlow/nixpkgs,SymbiFlow/nixpkgs,triton/triton,NixOS/nixpkgs,SymbiFlow/nixpkgs,SymbiFlow/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,SymbiFlow/nixpkgs,SymbiFlow/nixpkgs,SymbiFlow/nixpkgs,triton/triton,triton/triton,NixOS/nixpkgs,NixOS/nixpkgs,triton/triton,SymbiFlow/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,SymbiFlow/nixpkgs,NixOS/nixpkgs,SymbiFlow/nixpkgs,NixOS/nixpkgs,triton/triton,SymbiFlow/nixpkgs