Added an option to allow users to turn mangling off

        @options.mangle ?= true 
----

      if flags.minify
        if @concatCache[filePath]?.minifiedData
          result = @concatCache[filePath].minifiedData.toString 'utf8'
          concatenationChanged = false
        else
          result = minify concatenation, @options.mangle #argument passed to util for uglify
          @concatCache[filePath].minifiedData = new Buffer(result)

---

      minify = (js, mangle) ->
          jsp = uglify.parser
          pro = uglify.uglify
          ast = jsp.parse js
          ast = pro.ast_mangle ast if mangle #only mangle if option is true (default to true)
          ast = pro.ast_squeeze ast
          pro.gen_code ast