Add gutter and fade options to freetile js

Added options for gutter (margin) and fade.

Gutter adds a margin around all size. Defaults to 0. I thought this would be nice for users who don't want to add margins to their css for the selected elements.

fadeIn defaults to false and comes with an option for fadeInSpeed to control how fast/slow the fade in happens. This creates a nice smooth effect for loading the tiles if the tiles needed extra styles added while the layout was being set.

Updated the minified js and read me as well.