Merge branch 'master' into stdenv-updates.

Conflicts:
	pkgs/development/libraries/libxslt/default.nix

Commit 1764ea2b0a635587746d382db1b6cd832483a362 introduced changes to libxslt
in an awkward way to avoid re-builds on Linux. This patch has been simplified
during this merge.
pkgs/build-support/cabal: strip unnecessary --extra-lib-dir arguments for haskell packages

Packages that are registered in the ghc-pkg database don't need any
extra flags passed for Cabal to recognize them.
Merge remote-tracking branch 'origin/master' into stdenv-updates.
pkgs/build-support/cabal: updated recognition of Haskell packages for the directory new layout used in the stdenv-updates branch
perl: modify patch for better purity

This probably solves problems on some platforms that expose /usr and
/lib during build, see #386.
perl: enable doCheck, almost all tests work for me
Merge pull request #421 from vcunat/p/perl

Perl
icu: update to version 51.1
Merge remote-tracking branch 'origin/master' into stdenv-updates.
pkgs/build-support/cabal: fix spelling of the --extra-{include,lib}-dirs options to Cabal

It's quite amazing that we've managed to pass incorrectly spelled command line
flags to Cabal for ages without ever noticing. :-)

The search path options --extra-{include,lib}-dirs are usually unnecessary,
because the build environment is set up such that gcc and ld find those headers
and libraries automatically, i.e. without needing extra flags. The bubble burst
on MacOS X, though, where the build of haskell-text-icu couldn't find the icu
library without manually setting DYLD_LIBRARY_PATH in that build. Fortunately,
cabal takes care of that issue if a correctly spelled --extra-lib-dirs flag is
passed.
perl: disable one more test

It worked for me, but fails on hydra (probably not very pure).
perl: fix bash syntax

I thought I could make a small syntax change without trying, I was being
foolish.
perl: attempt to fix on FreeBSD by disabling two tests
Fix release-small.nix
perl: fix bad syntax in FreeBSD commit
libproxy: update to build with gcc47, add glib
dbus: modularize into libs, daemon, tools, tests and docs
dbus_glib: minor update, doCheck
systemd: minor update, changes for dbus split

New version with upstreamed changes from @edolstra :-)
dbus_* naming reorganization