webkitgtk: 2.4.6 -> 2.6.0
webkitgtk: keep previous version 2.4.6 as most clients depend on it
webkitgtk-2.4.6: depends on harfbuzz-icu.
Merge branch 'webkitgtk' of github.com:k0ral/nixpkgs into jumanji
New package: jumanji-20140622
Renamed glib_networking into glib-networking.
Clean-up in all-packages.nix