falcon: use new dsl

Formula/falcon.rb

@@ -7,19 +7,15 @@ class Falcon < Formula
 
   head 'http://git.falconpl.org/falcon.git'
 
+  option 'editline', "Use editline instead of readline"
+  option 'feathers', "Include feathers (extra libraries)"
+
   depends_on 'cmake' => :build
   depends_on 'pcre'
 
   conflicts_with 'sdl',
     :because => "Falcon optionally depends on SDL and then the build breaks. Fix it!"
 
-  def options
-    [
-      ['--editline', "Use editline instead of readline"],
-      ['--feathers', "Include feathers (extra libraries)"]
-    ]
-  end
-
   def install
     args = std_cmake_args + %W{
       -DCMAKE_INSTALL_PREFIX=#{prefix}
@@ -29,13 +25,13 @@ class Falcon < Formula
       -DFALCON_WITH_INTERNAL_PCRE=OFF
       -DFALCON_WITH_MANPAGES=ON}
 
-    if ARGV.include? '--editline'
+    if build.include? 'editline'
       args << "-DFALCON_WITH_EDITLINE=ON"
     else
       args << "-DFALCON_WITH_EDITLINE=OFF"
     end
 
-    if ARGV.include? '--feathers'
+    if build.include? 'feathers'
       args << "-DFALCON_WITH_FEATHERS=feathers"
     else
       args << "-DFALCON_WITH_FEATHERS=NO"