Make glib_networking available for dwbem
flightgear: 2.10.0 -> 2.12.0 (and make it run again)

The current FlightGear expression doesn't work:

  bash$ nix-build -A flightgear
  /nix/store/3c47sibzb9h1vhnn0gnh692hkpjc5p5v-flightgear-2.10.0

  bash$ ./result/bin/fgfs
  ERROR: The path '/nix/store/3c47sibzb9h1vhnn0gnh692hkpjc5p5v-flightgear-2.10.0/lib/FlightGear' does not exist in the file system.

  Base package check failed:
    Version [none] found at: /nix/store/3c47sibzb9h1vhnn0gnh692hkpjc5p5v-flightgear-2.10.0/lib/FlightGear
    Version 2.10.0 is required.
  Please upgrade/downgrade base package and set the path to your fgdata
  with --fg-root=path_to_your_fgdata

We could probably make the 2.10.0 version run, but I had already
upgraded it to 2.12.0 before I made it work. It seems only the data dir
configuration was wrong/missing: FG_DATA_DIR="$out/share/FlightGear/".

Simgear must be in version sync with flightgear, hence the upgrade.

Most of the diff is because I rewrote the flightgear expression to what
I think is the "new style". I wanted to add a preConfigure phase but
didn't understand why this expression had custom phases. So I just
rewrote the whole thing to something I consider more readable.
update dwb to the latest revision
experimental/vsftpd

vsftpd improvements:
- intorduce one declarative list of options
- make docummentation strings more understandable and add missing options
  such as SSL/TLS support
- Use environment.etc."vsftpd".text because I can't think about any
  reason why a shell script should be used.
  That code was written in 2009.
Adding FriBID browser plugin

FriBID is an open source software for the Swedish e-id system called
BankID. FriBID also supports processor architectures and Linux/BSD
distributions that the official software doesn't support.

https://fribid.se/index.en.html

FriBID plugin is a firefoxWrapper plugin. Enabled by setting:

  nixpkgs.config.enableFriBIDPlugin = true
munin: refactor package and add nixos service
Merge pull request #1090 from NixOS/munin-rework

munin: refactor package and add nixos service
Merge pull request #1050 from bjornfor/flightgear

flightgear: 2.10.0 -> 2.12.0 (and make it run again)
Merge pull request #918 from edwtjo/fribid-1.0.2

Adding FriBID browser plugin
Merge pull request #1054 from pSub/dwb-update

dwb fix and update
Merge pull request #1060 from MarcWeber/submit/vsftpd

small vsftpd improvements
Adding forktty terminal connection/disconnection helper