Gridster widget swapping positions though in browser zoom changes

[muralikrrish279]

Our application scenario more similar to this demo http://dsmorse.github.io/gridster.js/demos/resize-limits.html

If you change the browser zoom/resolution and reload the page, widgets are getting randomly placed though there col,row,x,y positions are hard-coded in the markup.

[dsmorse]

if you have a fix I'd gladly accept a PR