ekg2: use new dsl

Formula/ekg2.rb

@@ -1,22 +1,18 @@
 require 'formula'
 
-def use_libgadu?; ARGV.include? "--with-libgadu"; end
-
 class Ekg2 < Formula
-  url 'http://pl.ekg2.org/ekg2-0.3.1.tar.gz'
   homepage 'http://ekg2.org'
+  url 'http://pl.ekg2.org/ekg2-0.3.1.tar.gz'
   md5 '68fc05b432c34622df6561eaabef5a40'
 
   depends_on 'pkg-config' => :build
   depends_on 'readline'
-  depends_on 'libgadu' if use_libgadu?
+  depends_on 'libgadu' if build.include? "with-libgadu"
 
   # stripping breaks loading shared objects
   skip_clean :all
 
-  def options
-    [["--with-libgadu", "Compiles ekg2 with gadu-gadu support"]]
-  end
+  option "with-libgadu", "Compiles ekg2 with gadu-gadu support"
 
   def install
     readline = Formula.factory 'readline'
@@ -29,7 +25,7 @@ class Ekg2 < Formula
             "--without-gtk",
             "--enable-unicode"]
 
-    args << use_libgadu? ? "--with-libgadu" : "--without-libgadu"
+    args << build.include?("with-libgadu") ? "--with-libgadu" : "--without-libgadu"
 
     system "./configure", *args
     system "make install"