yabar-unstable: 2017-10-12 -> 2018-01-02

The unstable branch of `yabar` received some minor useful changes:

- Fixed missprint (https://github.com/geommer/yabar/commit/f1b1eff48108654219311e63147365cd6f006593)
- Update information on Debian installation (https://github.com/geommer/yabar/commit/ce20fe75f7bca2488168e45c577d6bb4996f7377)
- Add indicator to show current indicator using `libxkbcommon` (https://github.com/geommer/yabar/commit/5aa1fb5eb558f58f0bcfe495b8f49414aa6d88a2)

The last change requires a `libxkbcommon` as additional build input.

Furthermore I thought that it might be better to add the dependencies of
unstable (namely `playerctl` and `libxkbcommon`) to the `unstable.nix`
to reduce the closure size of the stable build.

pkgs/applications/window-managers/yabar/build.nix

@@ -2,7 +2,6 @@
 , xcbutilwm, alsaLib, wirelesstools, asciidoc, libxslt, makeWrapper, docbook_xsl
 , configFile ? null, lib
 , rev, sha256, version
-, playerctl
 }:
 
 stdenv.mkDerivation {
@@ -21,7 +20,6 @@ stdenv.mkDerivation {
   buildInputs = [
     cairo gdk_pixbuf libconfig pango xcbutilwm docbook_xsl
     alsaLib wirelesstools asciidoc libxslt makeWrapper
-    playerctl
   ];
 
   postPatch = ''
@@ -30,7 +28,7 @@ stdenv.mkDerivation {
       --replace "a2x" "${asciidoc}/bin/a2x --no-xmllint"
   '';
 
-  makeFlags = [ "DESTDIR=$(out)" "PREFIX=/" "PLAYERCTL=1" ];
+  makeFlags = [ "DESTDIR=$(out)" "PREFIX=/" ];
 
   postInstall = ''
     mkdir -p $out/share/yabar/examples