code: function( filePath , prefix ){
          try{
              var _content    = minjs.minify( filePath ).code.toString() ,
                  _filename   = prefix + MD5( _content ) + ".js";
              grunt.file.write( Path.join( config.dir.pubDir , _filename ) , _content );
          } catch( e ){
              E( "Error : uglifyJS error. check js file " + filePath );
          }
          return _filename;
      }
docs: /*!
  压缩文件
  @filePath   {string}    文件的目标地址
  @dest       {string}    保存的目标地址
  return      {string}