Darkcoin: new package (v0.9.13.15)

Darkcoin is a privacy-centered crypto-currency.
Litecoin: Update to 0.9.3-preview5

Now Litecoin expression lives in a single file, litecoin.nix
Fix the Vim Plugins Documentation
schismtracker: new package
Add package pidgin-window-merge
Add chronos, fault tolerant job scheduler for Mesos
mesos: update to 0.21.0
mesos: add docker support
fixes #5198
openvpn: 2.3.4 -> 2.3.6 (CVE-2014-8104)
openvpn: fix build
pythonPackages: ugly fix docker registry dependencies
Merge pull request #5195 from prikhi/fix-vimplugin-docu

Fix the Vim Plugins Documentation
Merge pull request #5201 from geerds/pidgin-window-merge

Add package pidgin-window-merge
skrooge: update from 1.3.2 to 1.10.0
Merge pull request #5209 from vbgl/skrooge

skrooge: update from 1.3.2 to 1.10.0
python-usbtmc: update 0.5 -> 0.6
wireshark: update from 1.12.1 to 1.12.2

Potentially fixes CVE-2014-8710, CVE-2014-8711, CVE-2014-8712,
CVE-2014-8713, CVE-2014-8714.
xmlrpc-c: update from 1.25.27 to 1.25.30
nss: security update fixing CVE-2014-1569