Add DeprecatedOption class.

Used to capture options that are being renamed.

Library/Homebrew/options.rb

@@ -32,6 +32,23 @@ class Option
   end
 end
 
+class DeprecatedOption
+  attr_reader :old, :current
+
+  def initialize(old, current)
+    @old = old
+    @current = current
+  end
+
+  def old_flag
+    "--#{old}"
+  end
+
+  def current_flag
+    "--#{current}"
+  end
+end
+
 class Options
   include Enumerable
 

Library/Homebrew/test/test_options.rb

@@ -25,6 +25,20 @@ class OptionTests < Homebrew::TestCase
   end
 end
 
+class DeprecatedOptionTests < Homebrew::TestCase
+  def setup
+    @deprecated_option = DeprecatedOption.new("foo", "bar")
+  end
+
+  def test_old
+    assert_equal "foo", @deprecated_option.old
+  end
+
+  def test_current
+    assert_equal "bar", @deprecated_option.current
+  end
+end
+
 class OptionsTests < Homebrew::TestCase
   def setup
     @options = Options.new