added merge option to jade serializer to support merging specified attributes with attributes available from instance
added merge option to jade serializer to support merging specified attributes with attributes available from instance

dy-paiva/jader,dy-paiva/jader,zohararad/jader,mumaoxi/jader,dy-paiva/jader,zohararad/jader,zohararad/jader,mumaoxi/jader,mumaoxi/jader