uhd: new package

UHD is USRP Hardware Driver (for Software Defined Radio).
Add fftwFloat => fftw composition with floating point

Needed for Gnuradio (coming in next commit).
gnuradio: new package

Add GNU Radio, the free & open-source software development toolkit that
provides signal processing blocks to implement software radios.
gutenprint: upgrade to 5.2.9
gutenprint: fix the cupsd driver
libvirtd: add missing dependency on dnsmasq

Fixes this:

Nov 09 16:13:27 nixos-laptop systemd[1]: Starting Libvirt Virtual Machine Management Daemon...
Nov 09 16:13:28 nixos-laptop .libvirtd-wrapp[17183]: libvirt version: 1.1.4
Nov 09 16:13:28 nixos-laptop .libvirtd-wrapp[17183]: Cannot check dnsmasq binary dnsmasq: No such file or directory
Nov 09 16:13:28 nixos-laptop .libvirtd-wrapp[17183]: Cannot check dnsmasq binary dnsmasq: No such file or directory
Nov 09 16:13:28 nixos-laptop systemd[1]: Started Libvirt Virtual Machine Management Daemon.
nixos/libvirtd-service: fix for dnsmasq (dir perms 700 -> 755)

Fixes this:

Nov 09 16:18:54 nixos-laptop systemd[1]: Starting Libvirt Virtual Machine Management Daemon...
Nov 09 16:18:54 nixos-laptop dnsmasq[15809]: read /etc/hosts - 2 addresses
Nov 09 16:18:54 nixos-laptop dnsmasq[15809]: failed to load names from /var/lib/libvirt/dnsmasq/default.addnhosts: Permission denied
Nov 09 16:18:54 nixos-laptop dnsmasq[15809]: cannot read /var/lib/libvirt/dnsmasq/default.hostsfile: Permission denied
Nov 09 16:18:55 nixos-laptop systemd[1]: Started Libvirt Virtual Machine Management Daemon.

I don't understand the reason for the original 700 permission bits.
Apparently read-access is needed and Ubuntu also use 755 perms.

Use "chmod" instead of "mkdir -m" to set permissions because mkdir doesn't
modify permissions on existing directories.
New package: LDM - Lightweight device mounter

Signed-off-by: Moritz Ulrich <moritz@tarn-vedra.de>
uhd: bump 3.5.2 -> 3.5.4

It seems upstream changed the hash of the 3.5.2 archive so it doesn't
build anymore. Bump it instead of just updating the hash.
gutenprint: wrap sbin/cups-genppd.5.2

This is used to generate ppd files for cups:

  $ cups-genppd.5.2 -M | grep p50
  canon-cp500
  escp2-p50
  $ cups-genppd.5.2 -p . escp2-p50

This will create the relevant ppd file in the current directory. This
can then be used by cups after setting services.drivers.drivers =
[pkgs.gutenprint]; and configuring the printer to use this ppd e.g.
via the web interface on http://localhost:631
xawtv: 3.95 -> 3.103

- package now builds on linux
- added linux platforms
- removed patches
remmina: add meta.platforms
pciutils: minor update to today's version
gimp: change default from 2.6 to 2.8
gimpPlugins.ufraw: update plugin from 0.15 to 0.19.2 to build with gimp 2.8
gimpPlugins.texturize: fix compilation with gimp 2.8
gimpPlugins.fourier: upgrade from 0.3.3 to 0.4.1 and fix compilation
gimpPlugins.gmic: upgrade from 1.3.2.0 to 1.5.7.4, fix compilation with gimp 2.8

Only the gimp plugin is built now, as the rest of the suite is quite
large and probably deserves its own package.
Updating ts to 0.7.4.
Don't set the default channel to 13.10 when installing from master

Partial revert of 619a1f561480a300ce28f0f471e73fecda85fd60.