diffutils: minor stable update 3.2 -> 3.3
linux: use 3.4 as the default (latest longterm)

CC #501
gzip: update 1.5 -> 1.6, use less in tests now
acl: minor update 2.2.51 -> 2.2.52
attr: minor update 2.4.46 -> 2.4.47
gmp5: minor update 5.1.1 -> 5.1.2 and file rename
mpfr: only use 3.1.2 and drop 3.1.1

I tried some packages, all seem to compile fine.
gawk: update 4.0.2 -> 4.1.0
file: minor update 5.12 -> 5.14
pcre: minor update 8.32 -> 8.33
binutils: minor update 2.23.1 -> .2
texinfo5: add missing xz, use version 5.* by default
libssh: non-critical security update CVE-2013-0176
libarchive: update 3.0.4 -> 3.1.2, homepage move
stdenv: default builder fixes (merge #554)

With a minor fix.
I did some huge rebuilds with this on x86_64-linux, found no problems.