libqglviewer: use options dsl

Formula/libqglviewer.rb

@@ -5,24 +5,15 @@ class Libqglviewer < Formula
   url 'http://www.libqglviewer.com/src/libQGLViewer-2.3.17.tar.gz'
   sha1 '03b1da73bdb07988184c1f5d7c1c360be27b2a0e'
 
+  option :universal
+
   depends_on 'qt'
 
-  def options
-    [
-      ['--universal', "Build both x86_64 and x86 architectures."],
-    ]
-  end
-
-  def patches
-    DATA
-  end
+  def patches; DATA; end
 
   def install
     args = ["PREFIX=#{prefix}"]
-
-    if ARGV.include? '--universal'
-      args << "CONFIG += x86 x86_64"
-    end
+    args << "CONFIG += x86 x86_64" if build.unversal?
 
     cd 'QGLViewer' do
       system "qmake", *args
@@ -30,10 +21,9 @@ class Libqglviewer < Formula
     end
   end
 
-  def caveats
-     <<-EOS.undent
-      To avoid issues with runtime linking and facilitate usage of the library:
-        sudo ln -s "#{prefix}/QGLViewer.framework" "/Library/Frameworks/QGLViewer.framework"
+  def caveats; <<-EOS.undent
+    To avoid issues with runtime linking and facilitate usage of the library:
+      sudo ln -s "#{prefix}/QGLViewer.framework" "/Library/Frameworks/QGLViewer.framework"
     EOS
   end
 end