add image preview in table view

Add an image preview in table view. This adds a small preview image of the listed image. The added class "preview" allows for JavaScripts based zoom functionality in user based templates.

Sample zoom functionality:
```javascript
jQuery(function() {
	/* CONFIG */
		
		xOffset = 10;
		yOffset = 30;
		
		// these 2 variable determine popup's distance from the cursor
		// you might want to adjust to get the right result
		
	/* END CONFIG */
	jQuery("img.preview").hover(function(e){
		this.t = this.title;
		this.title = "";	
		var c = (this.t != "") ? "<br/>" + this.t : "";
		jQuery("body").append("<p id='preview'><img src='"+ this.src +"' alt='Image preview' />"+ c +"</p>");								 
		jQuery("#preview")
			.css("top",(e.pageY - xOffset) + "px")
			.css("left",(e.pageX + yOffset) + "px")
			.css("max-width","300px")
			.css("max-height","300px")
			.css("position", "absolute")
			.fadeIn("fast");						
    },
	function(){
		this.title = this.t;	
		jQuery("#preview").remove();
    });	
	jQuery("img.preview").mousemove(function(e){
		jQuery("#preview")
			.css("top",(e.pageY - xOffset) + "px")
			.css("left",(e.pageX + yOffset) + "px")
			.css("position", "absolute");

	});			
});
```