locate service: allow customisation

Fixes #2961
fix openjdk url for Darwin
Fixed settings issue.

The following warning was shown when I clicked on links:
'GLib-GIO-Message: Using the 'memory' GSettings backend. Your settings will not be saved or shared with other applications.'
numexpr: Define license
tables: Define license
szip: Indentation
szip: Provide meta-data

The license is set to "unfree" as commercial use is not permitted by the
license [1].

[1]: http://www.hdfgroup.org/doc_resource/SZIP/Commercial_szip.html
Update `macvim` package to v7.4.355

MacVim's maintenance has stagnated, so this moves `macvim` to a new maintainer.
Additionally, the `-headerpad_max_install_names` linker flag is passed to
prevent problems when setting the rpaths.
haskell-hlibgit2: re-generate with cabal2nix
haskell-gtkglext: re-generate with cabal2nix
haskell-packages.nix: delete obsolete 'gtk2hsC2hs' alias
Merge pull request #3189 from aherrmann/pr_licenses

License meta-data for numexpr, tables, and szip
Merge pull request #2963 from Fuuzetsu/locate

locate service: allow customisation
pretty: new haskell package
Upgrade rsyslog to latest (v7) stable release. Added liblogging (new dependency of rsyslog).
Revert "pretty: new haskell package"

This reverts commit 51dc75b7692ce41527685507ea7f6f5dc2cb6ec5. The pretty
library is a core package since (at least) GHC 6.10.4, i.e. every single one of
our compilers ships this library by default. Adding the package to the global
namespace like this is almost certainly going to cause trouble because we'll
end up with inconsistently linked binaries whenever packages mix the user-space
pretty library with the core one.
mediawiki: add patch for fixing postgresql errors
linux: Update to 3.12.24

CVE-2014-4508, CVE-2014-0206.
libxklavier: fix not finding xkbcomp (fixes #3173)

Also refactor the expression a bit,
and add description+license.
xfce4-xkb-plugin: maintenance update