Add Apple command-line tools

Closes #4365
r-XML: adding system-dependency libxml2
Revert "ghostscriptX: update from 9.06 to 9.14, potentially fixes CVE-2012-4405"

This reverts commit 13fab57d127bf70a338901b422da32e562d16889.

Hopefully fixes the printing tests at
http://hydra.nixos.org/build/14952070/log/raw ; if not, it's probably
gutenprint although I doubt:

client# lp: Unsupported document-format "application/pdf".
cmplayer: fix build
xen: note about security for next bump
linux-man-pages: Update to version 3.73.

Signed-off-by: aszlig <aszlig@redmoonstudios.org>
agda-base: new package
telepathy: 0.5.3 -> 0.8.80
Specify unfree license for Opera browser
Make path to Xcode configurable
tibia: update to 10.57
webkitgtk: bump to version 2.4.6
logstalgia: update from 1.0.3 to 1.0.5 and adopt it
XBMC AdvancedLauncher RetroArch launchers.

These are wrappers for retroarch wrappers, they are needed since launching a
process from XBMC(as a display manager and probably otherwise), using
AdvancedLauncher, results in it and it's parent recieving the same gamepad
input.

These wrappers will produce no sound on XBMC and AdvancedLauncher setups not
using a sound daemon, since XBMC gets paused while still holding onto the sound
device.
xbmc: enable plugins to be picked up from the store.
xmbcPlugins: svtplay added
Syntax fix for xbmc/retroarch in all-packages.nix
pythonPackages.webob: 1.3.1 -> 1.4
Merge pull request #4371 from joachifm/webkit_2_4_6

webkitgtk: bump to version 2.4.6
Merge pull request #3963 from christopherpoole/geant4

Add the Geant4 Monte Carlo radiation transport toolkit and its Python bindings.