Merge #2798: stdenv and a few other big updates

Stdenv-changing things:
    - gcc 4.8.2 -> 4.8.3
    - long-running grsecurity branch
Others:
    - pkgconfig update
    - CVE for libtasn1, dbus

Conflicts (simple):
    pkgs/development/compilers/ghc/7.6.3.nix