networkmanager: fix path to 'openconnect' binary

Without this the openconnect VPN plugin doesn't work:

  NetworkManager[830]: <warn> VPN connection 'Foo VPN' failed to connect: 'Could not find openconnect binary.'.
libreoffice: Fix path to Ant
linuxHeaders: add meta, incl. platforms = linux;

Noted by @mornfall. The built package has ~5 MB uncompressed,
but just the Linux tarball has ~40 MB compressed...
haskell bytestring-progress: Disable haddock to avoid a build failure.
linux-perf: Fix build (unportable shell hack broke).
mpc: (mpd client) Update to 0.25.
emacs: Allow non-GTK X11 builds (--with-x-toolkit=lucid).
STP: Simple Theorem Prover (a SMT solver for bitvectors & arrays).
nixos: Add a dictd service.
perl-Devel-SizeMe: A module for dumping heap use and structure.
perl-Mojolicious: A real-time web framework.
haskell: Add an atto-lisp package.
Re-generate some Haskell expressions with cabal2nix.
add ibus
pianobooster: patch to build with gcc4.7, wrap it so it finds libGL.so.1

Also add linux as a platform.

Patches from:
https://github.com/gbin/gbin-overlay/tree/master/media-sound/pianobooster
Merge pull request #1588 from ocharles/pythonPackages.tarsnapper

pythonPackages.tarsnapper: New expression
photivo: Update.
photivo: Fix paths.
libreoffice: Fix path to the JDK
Add #include <unisted.h> for sleep and usleep