add Copy builder as a copy of Install

lib/rscons.rb

@@ -22,8 +22,9 @@ module Rscons
   # Names of the default builders which will be added to all newly created
   # {Environment} objects.
   DEFAULT_BUILDERS = [
-    :Command,
     :CFile,
+    :Command,
+    :Copy,
     :Directory,
     :Disassemble,
     :Install,

lib/rscons/builders/install.rb

@@ -54,6 +54,10 @@ module Rscons
         target if (target_is_dir ? Dir.exists?(target) : File.exists?(target))
       end
 
+
     end
+
+    class Copy < Install; end
+
   end
 end