Add support for global LXC config files
pythonPackages: add pyalgotrade
pythonPackages: add scikit-learn
dnscrypt-proxy: new expression
Add dnscrypt-proxy service

The dnscrypt-proxy service relays regular DNS queries to
a DNSCrypt enabled upstream resolver.
The traffic between the client and the upstream resolver is
encrypted and authenticated, which may mitigate the risk of
MITM attacks and third-party snooping (assuming a trustworthy
upstream).

Though dnscrypt-proxy can run as a standalone DNS client,
the recommended setup is to use it as a forwarder for a
caching DNS client.
To use dnscrypt-proxy as a forwarder for dnsmasq, do

```nix
{
  # ...

  networking.nameservers = [ "127.0.0.1" ];
  networking.dhcpcd.extraConfig = "nohook resolv.conf";

  services.dnscrypt-proxy.enable = true;
  services.dnscrypt-proxy.localAddress = "127.0.0.1";
  services.dnscrypt-proxy.port = 40;

  services.dnsmasq.enable = true;
  services.dnsmasq.extraConfig = ''
    no-resolv
    server=127.0.0.1#40
    listen-address=127.0.0.1
  '';

  # ...
}
```
prl-tools: add package
nixos/parallels-guest: add options
nix-exec: make git less heavyweight
git: do not do install-doc when !withManual
volatility: upgrade to 2.4
Merge pull request #4573 from fpletz/feature/lxc-configuration

Add support for global LXC config files
Merge pull request #4578 from offlinehacker/pkgs/pythonPackages/scikit_algo

pythonPackages: scikit-learn and pyalgotrade
fix travis eval and remove duplicate
Merge pull request #4929 from abbradar/prl-tools

Add packages and support for Parallel Guest Tools
Merge pull request #4950 from joachifm/dnscrypt-proxy

dnscrypt-proxy service
flashplayer: Update from 11.2.202.411 -> 11.2.202.418
Merge pull request #4967 from bosu/vol2.4

volatility: upgrade to 2.4
winpdb: new package

Platform independent Python debugger.

http://winpdb.org/

Tested by debugging a Python script on Linux.
Add local-fs.target to minidlna.

Minidlna fails to start if it wants to access a filesystem which isn't
mounted (yet).
zmq: initial package