efl: use vanilla pkg-config

Use vanilla pkg-config to build EFL applications.

The EFL library has a set of pkg-config files (*.pc) which uses
private requirements. The default pkg-config setup on nixpkgs is
patched to disable resolving those requirements. See
http://bugs.freedesktop.org/show_bug.cgi?id=4738 for reference.

As a consequence each package depending on efl has to explicitly set
the search path in order to be able to find the corresponding header
files.

By using vanilla pkg-config this is not necessary (and this is the
expected behaviour for pkg-config), allowing simpler nix expressions.

pkgs/desktops/enlightenment/enlightenment.nix

···
 { stdenv, fetchurl, pkgconfig, efl, xcbutilkeysyms, libXrandr, libXdmcp,
 libxcb, libffi, pam, alsaLib, luajit, bzip2, libpthreadstubs, gdbm, libcap,
-mesa_glu, xkeyboard_config }:
+mesa_glu, xkeyboard_config, pcre }:
 
 stdenv.mkDerivation rec {
   name = "enlightenment-${version}";
···
     sha256 = "0w5f3707hyfc20i6xqh4jlr5p2yhy1z794061mjsz2rp4w00qmpb";
   };
 
-  nativeBuildInputs = [ pkgconfig ];
+  nativeBuildInputs = [ (pkgconfig.override { vanilla = true; }) ];
 
   buildInputs = [
     efl libXdmcp libxcb xcbutilkeysyms libXrandr libffi pam alsaLib
-    luajit bzip2 libpthreadstubs gdbm
+    luajit bzip2 libpthreadstubs gdbm pcre
   ] ++
     stdenv.lib.optionals stdenv.isLinux [ libcap ];
-
-  NIX_CFLAGS_COMPILE = [
-    "-I${efl}/include/ecore-imf-1"
-    "-I${efl}/include/emile-1"
-    "-I${efl}/include/eo-1"
-    "-I${efl}/include/ethumb-1"
-    "-I${efl}/include/ethumb-client-1"
-  ];
 
   preConfigure = ''
     export USER_SESSION_DIR=$prefix/lib/systemd/user

pkgs/desktops/enlightenment/ephoto.nix

···
-{ stdenv, fetchurl, pkgconfig, efl, curl, makeWrapper }:
+{ stdenv, fetchurl, pkgconfig, efl, pcre, curl, makeWrapper }:
 
 stdenv.mkDerivation rec {
   name = "ephoto-${version}";
···
     sha256 = "09kraa5zz45728h2dw1ssh23b87j01bkfzf977m48y1r507sy3vb";
   };
 
-  nativeBuildInputs = [ pkgconfig makeWrapper ];
-
-  buildInputs = [ efl curl ];
+  nativeBuildInputs = [ (pkgconfig.override { vanilla = true; }) makeWrapper ];
 
-  NIX_CFLAGS_COMPILE = [
-    "-I${efl}/include/ecore-con-1"
-    "-I${efl}/include/ecore-evas-1"
-    "-I${efl}/include/ecore-imf-1"
-    "-I${efl}/include/ecore-input-1"
-    "-I${efl}/include/eet-1"
-    "-I${efl}/include/eldbus-1"
-    "-I${efl}/include/emile-1"
-    "-I${efl}/include/ethumb-1"
-    "-I${efl}/include/ethumb-client-1"
-  ];
+  buildInputs = [ efl pcre curl ];
 
   postInstall = ''
     wrapProgram $out/bin/ephoto --prefix LD_LIBRARY_PATH : ${curl.out}/lib

pkgs/desktops/enlightenment/rage.nix

···
-{ stdenv, fetchurl, pkgconfig, efl, gst_all_1, curl, wrapGAppsHook }:
+{ stdenv, fetchurl, pkgconfig, efl, gst_all_1, pcre, curl, wrapGAppsHook }:
 
 stdenv.mkDerivation rec {
   name = "rage-${version}";
···
   };
 
   nativeBuildInputs = [
-    pkgconfig
+    (pkgconfig.override { vanilla = true; })
     wrapGAppsHook
   ];
 
···
     gst_all_1.gst-plugins-good
     gst_all_1.gst-plugins-bad
     gst_all_1.gst-libav
+    pcre
     curl
  ];
-
-  NIX_CFLAGS_COMPILE = [
-    "-I${efl}/include/ecore-con-1"
-    "-I${efl}/include/ecore-evas-1"
-    "-I${efl}/include/ecore-file-1"
-    "-I${efl}/include/ecore-imf-1"
-    "-I${efl}/include/ecore-input-1"
-    "-I${efl}/include/eet-1"
-    "-I${efl}/include/efreet-1"
-    "-I${efl}/include/eldbus-1"
-    "-I${efl}/include/emile-1"
-    "-I${efl}/include/eo-1"
-    "-I${efl}/include/ethumb-1"
-    "-I${efl}/include/ethumb-client-1"
-  ];
 
   postInstall = ''
     wrapProgram $out/bin/rage --prefix LD_LIBRARY_PATH : ${curl.out}/lib

pkgs/desktops/enlightenment/terminology.nix

···
-{ stdenv, fetchurl, pkgconfig, efl, curl, makeWrapper }:
+{ stdenv, fetchurl, pkgconfig, efl, pcre, curl, makeWrapper }:
 
 stdenv.mkDerivation rec {
   name = "terminology-${version}";
···
     sha256 = "13rl1k22yf8qrpzdm5nh6ij641fibadr2ww1r7rnz7mbhzj3d4gb";
   };
 
-  nativeBuildInputs = [ pkgconfig makeWrapper ];
-
-  buildInputs = [ efl curl ];
+  nativeBuildInputs = [ (pkgconfig.override { vanilla = true; }) makeWrapper ];
 
-  NIX_CFLAGS_COMPILE = [
-    "-I${efl}/include/ecore-con-1"
-    "-I${efl}/include/eldbus-1"
-    "-I${efl}/include/elocation-1"
-    "-I${efl}/include/emile-1"
-    "-I${efl}/include/eo-1"
-    "-I${efl}/include/ethumb-1"
-  ];
+  buildInputs = [ efl pcre curl ];
 
   postInstall = ''
     for f in $out/bin/*; do