zfs-0.6.2 and spl-0.6.2

Enable parallelBuilding, too.
Add lens-datetime haskell library
Merge pull request #863 from errge/lensdatetime

Add lens-datetime haskell library
haskell-distributed-process: drop broken package

distributed-process won't compile, and upstream doesn't accept bug reports
without some elaborate registration procedure.
qemu: Revert to 1.5.2

1.6.0 breaks many VM builds because it gives incorrect RTC values to
the guest.  See

  http://hydra.nixos.org/eval/981543
  http://hydra.nixos.org/eval/981440
Add noHaddock flag to modular-artihmetic

Building of haddock for packages with UTF-8 source is already
fixed in the stdenv-updates branch.  This fixes modular-arithmetic
until that branch is merged.  Will send another pull request to
add back haddock for that branch.
libav: major update and refactoring (close #839)

Also leaving 0_8 branch, as it's compatible with older ffmpeg versions.
I'm planning that all expressions will be able to switch easily
between ffmpeg and libav (whatever default we choose, but I prefer libav).

Edited (twice) according to notes on the reverted b003138.
Make generated node expression overridable in nodePackages.
nvidia-x11: Update to 319.49
linux: Update to 3.4.59
git-and-tools/hub: Update to version 1.10.6.

This now uses fetchurl instead of fetchgit to speed up fetching.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
boomerang: Refactor and fix build.

Thanks to @phreedom for reporting the broken URL used fetchgit, which
was because I deleted my fork repository. Fortunately, in the meantime
other forks got to a more "working" state and being more actively
maintained than my fork. So that's why I switched using @nemerle's fork
now, as it is the the most usable one out there, at least in our case.

One stupid thing I've done in the first place was to use "1.0pre" as the
version and the fork uses "alpha 0.3.2", so it essentially is some kind
of a "downgrade" if you just look at the version.

Fortunately, peer-unreviewed research based on guesswork has shown that
I'm the only one using Boomerang on NixOS, so this shouldn't have a big
impact on the other non-existent users.

Also, this drops dependencies on boehmgc and cppunit, because building
with either one or both will fail at the moment.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
Updated id3lib to avoid building its own zlib, fixes #867
Merge pull request #862 from jcumming/zfs.130823

zfs-0.6.2 and spl-0.6.2
Merge pull request #866 from errge/haddockutf

Add noHaddock flag to modular-artihmetic
xmlrpc-c: update old svn -> latest stable (v1.25.25)

Also:
 - install the "xmlrpc" tool, similar to the Debian/Ubuntu package
 - add meta.* attributes
haskell-network-multicast: update to version 0.0.8
haskell-texmath: update to version 0.6.4
haskell-hoogle: update to version 4.2.20