Add body class to detect how many col showing now

Add body class like how many cols showing now :

Classes look like `<body class="col-1">` = one col showing

So you can detect for CSS  if one col showing 

Ex: 

`.col-1 #grid > .item > .children 	{max-width:310px;}`
`.col-2 #grid > .item > .children 	{max-width:640px;}`


..... for more better control