eclipse: add webkit as dependency

This makes the Eclipse internal web browser work.

The internal web browser is the default browser, and Eclipse requires
manual configuration for any other (external) web browser. To me this
means the internal browser should be working by default, unless users
will get an error popup if they click any links.

This change increases the closure size from 714 to 880 MiB
(attribute eclipses.eclipse_cpp_43).

pkgs/applications/editors/eclipse/default.nix

@@ -1,6 +1,7 @@
 { stdenv, fetchurl, makeDesktopItem, makeWrapper
 , freetype, fontconfig, libX11, libXext, libXrender, zlib
 , glib, gtk, libXtst, jre
+, webkitgtk2 ? null  # for internal web browser
 }:
 
 assert stdenv ? glibc;
@@ -44,7 +45,7 @@ let
         
         makeWrapper $out/eclipse/eclipse $out/bin/eclipse \
           --prefix PATH : ${jre}/bin \
-          --prefix LD_LIBRARY_PATH : ${glib}/lib:${gtk}/lib:${libXtst}/lib \
+          --prefix LD_LIBRARY_PATH : ${glib}/lib:${gtk}/lib:${libXtst}/lib${stdenv.lib.optionalString (webkitgtk2 != null) ":${webkitgtk2}/lib"} \
           --add-flags "-configuration \$HOME/.eclipse/''${productId}_$productVersion/configuration"
 
         # Create desktop item.