Fix big-parallel usage

requiredSystemFeatures is not a meta attribute but a derivation
attribute. So "big-parallel" was being ignored on e.g. chromium,
causing it to be built (and timing out) on slow machines.

http://hydra.nixos.org/build/45819778#tabs-buildsteps

pkgs/applications/networking/browsers/chromium/browser.nix

@@ -42,13 +42,14 @@ mkChromiumDerivation (base: rec {
 
   passthru = { inherit sandboxExecutableName; };
 
+  requiredSystemFeatures = [ "big-parallel" ];
+
   meta = {
     description = "An open source web browser from Google";
     homepage = http://www.chromium.org/;
     maintainers = with maintainers; [ chaoflow ];
     license = licenses.bsd3;
     platforms = platforms.linux;
     hydraPlatforms = if channel == "stable" then ["x86_64-linux"] else [];
-    requiredSystemFeatures = [ "big-parallel" ];
   };
 })

pkgs/applications/office/libreoffice/default.nix

@@ -251,13 +251,14 @@ in stdenv.mkDerivation rec {
     inherit srcs;
   };
 
+  requiredSystemFeatures = [ "big-parallel" ];
+
   meta = with lib; {
     description = "Comprehensive, professional-quality productivity suite, a variant of openoffice.org";
     homepage = http://libreoffice.org/;
     license = licenses.lgpl3;
     maintainers = with maintainers; [ viric raskin ];
     platforms = platforms.linux;
     hydraPlatforms = [];
-    requiredSystemFeatures = [ "big-parallel" ];
   };
 }

pkgs/applications/office/libreoffice/still.nix

@@ -254,12 +254,13 @@ in stdenv.mkDerivation rec {
     inherit srcs;
   };
 
+  requiredSystemFeatures = [ "big-parallel" ];
+
   meta = with lib; {
     description = "Comprehensive, professional-quality productivity suite (Still/stable release)";
     homepage = http://libreoffice.org/;
     license = licenses.lgpl3;
     maintainers = with maintainers; [ viric raskin ];
     platforms = platforms.linux;
-    requiredSystemFeatures = [ "big-parallel" ];
   };
 }

pkgs/desktops/gnome-3/3.20/apps/evolution/default.nix

@@ -35,12 +35,13 @@ in stdenv.mkDerivation rec {
 
   enableParallelBuilding = true;
 
+  requiredSystemFeatures = [ "big-parallel" ];
+
   meta = with stdenv.lib; {
     homepage = https://wiki.gnome.org/Apps/Evolution;
     description = "Personal information management application that provides integrated mail, calendaring and address book functionality";
     maintainers = gnome3.maintainers;
     license = licenses.lgpl2Plus;
     platforms = platforms.linux;
-    requiredSystemFeatures = [ "big-parallel" ];
   };
 }

pkgs/desktops/gnome-3/3.22/apps/evolution/default.nix

@@ -35,12 +35,13 @@ in stdenv.mkDerivation rec {
 
   enableParallelBuilding = true;
 
+  requiredSystemFeatures = [ "big-parallel" ];
+
   meta = with stdenv.lib; {
     homepage = https://wiki.gnome.org/Apps/Evolution;
     description = "Personal information management application that provides integrated mail, calendaring and address book functionality";
     maintainers = gnome3.maintainers;
     license = licenses.lgpl2Plus;
     platforms = platforms.linux;
-    requiredSystemFeatures = [ "big-parallel" ];
   };
 }