Add zfs module.
Need extraModulePackages for spl and zfs modules.
Add the hostid option. Refactor code a bit better for initrd(untested) and system operation.
spl module params in boot.spl.*
Support driSupport32Bit for nvidia legacy 304.

I need this for steam to work with some older cards.
Merge remote-tracking branch 'upstream/master'
Fix (and simplify) the blcr module.
add xbmc window manager
modules/config/fonts.nix: export GDFONTPATH in /etc/profile

Set the environment variable GDFONTPATH to the list of directories where fonts
are expected to be installed. This is search path is used by same GD-based
applications, such as Gnuplot.

Alternatively, we could rely on fontconfig to achieve the same thing, i.e. by
running

  for n in $(fc-list | sed -r -e 's|^([^:]+):.*$|\1|'); do echo $(dirname "$n"); done | sort | uniq

to get that list at run-time, but the static approach feels more deterministic.
modules/config/fonts.nix: revert "export GDFONTPATH in /etc/profile"

This reverts commit 2802538dc2e2a8923e3d3cc3e144abc4e1561760. The idea
was good, but unfortunately $GDFONTPATH has a different format, i.e.
programs that use this variable don't descend into the directories
listed here like fontconfig does, so we cannot use the same values for
both settings.
Merge pull request #90 from iElectric/xbmc

Add xbmc window manager
nixos-rebuild build-vm: Override filesystems defined in the normal config
Log the configuration when booting / switching
Websockify: End descriptions with a period.
websockify: Add unit descriptions
default-websockify: Stop when reconfigured (i.e. new ports added/removed)
Add boot.initrd.compressor option
x11/mesa: driSupport32Bit for the mesa implementation
Merge pull request #70 from cpages/master

Support driSupport32Bit for nvidia legacy 304
Merge pull request #86 from maggesi/blcr-updates

blcr module: fix (and simplify)