Environment#print_builder_run_message should support string commands - close #44

lib/rscons/builders/directory.rb

@@ -20,8 +20,7 @@ module Rscons
           Ansi.write($stderr, :red, "Error: `#{target}' already exists and is not a directory", :reset, "\n")
           false
         else
-          desc = "Directory #{target}"
-          env.print_builder_run_message(desc, desc)
+          env.print_builder_run_message("Directory #{target}", nil)
           cache.mkdir_p(target)
           target
         end

lib/rscons/builders/install.rb

@@ -43,8 +43,7 @@ module Rscons
           # Check the cache and copy if necessary
           unless cache.up_to_date?(dest, :Copy, [src], env)
             unless printed_message
-              desc = "#{name} #{target}"
-              env.print_builder_run_message(desc, desc)
+              env.print_builder_run_message("#{name} #{target}", nil)
               printed_message = true
             end
             cache.mkdir_p(File.dirname(dest))