iio-sensor-proxy: init at 2.2 and nixos module

This PR adds support for ```iio-sensor-proxy``` used by GNOME v3 and
others for reading data from the accelerometer, gps, compass and similar sensors
built into some relatively recent laptops.

Additionally, there is a NixOS module exposed via hardware.sensor.iio
for enabling services, udev rules and dbus services.

pkgs/os-specific/linux/iio-sensor-proxy/default.nix

@@ -0,0 +1,47 @@
+{ stdenv, fetchFromGitHub, autoconf-archive, gettext, libtool, intltool, autoconf, automake
+, glib, gtk3, gtk_doc, libgudev, pkgconfig, systemd }:
+
+stdenv.mkDerivation rec {
+  name = "iio-sensor-proxy-${version}";
+  version = "2.2";
+
+  src = fetchFromGitHub {
+    owner  = "hadess";
+    repo   = "iio-sensor-proxy";
+    rev    = version;
+    sha256 = "1x0whwm2r9g50hq5px0bgsrigy8naihqgi6qm0x5q87jz5lkhrnv";
+  };
+
+  configurePhase = ''
+    ./autogen.sh --prefix=$out \
+      --with-udevrulesdir=$out/lib/udev/rules.d \
+      --with-systemdsystemunitdir=$out/lib/systemd/system
+  '';
+
+  buildInputs = [
+    glib
+    gtk3
+    gtk_doc
+    libgudev
+    systemd
+  ];
+
+  nativeBuildInputs = [
+    autoconf
+    autoconf-archive
+    automake
+    gettext
+    intltool
+    libtool
+    pkgconfig
+  ];
+
+  meta = with stdenv.lib; {
+    description = "Proxy for sending IIO sensor data to D-Bus";
+    homepage = https://github.com/hadess/iio-sensor-proxy;
+    license = licenses.gpl3 ;
+    maintainers = with maintainers; [ peterhoeg ];
+    platforms = platforms.linux;
+    inherit version;
+  };
+}