Add oldindex property to sortupdate event data

knowing the old index is a useful feature for using this in an MVVC application, since the underlying array can be spliced instead of having to be rewritten.

AngularJS example:

```javascript
function SortableCTRL($scope) {
	$scope.sortableArray = ['One', 'Two', 'Three'];
	
	$scope.sortupdate = function(e, data) {
		var start = data.oldindex,
			end   = data.item.index();
		
		$scope.sortableArray.splice(end, 0,
			$scope.sortableArray.splice(start, 1)[0]);
		
		$scope.$apply();
	};
	
	setTimeout(function() {
		$('#sortable')
			.sortable()
			.on('sortupdate', $scope.sortupdate);
	});
}```
during ‘destroy’, remove event handlers added with ‘.on('sortupdate', …)’
Merge branch 'patch-1'
Update jquery.sortable.js

Added option for placeholder
- added custom markup for placeholder as option, useful when using with tables.
Example :
	// JS CODE
	$('table.data tbody').sortable(
	{  
		items: 'tr' ,
		placeholder : '<tr><td colspan="7">&nbsp;</td></tr>'
	}) ;

	// CSS STYLE FOR TR > TD
	.sortable-placeholder td
	{
		background:#FFFEB8;
		height:100px;
		width:100%;
		
	}
Support vertical lists of variable height by defining a dead zone when hovering over larger items.
add reload method
Fix false negative bug when dropping onto same index in new container.
Updated README.md
add reload method
Merge https://github.com/rodolfospalenza/html5sortable into HEAD
Update README
Update README
Merge https://github.com/bistoco/html5sortable
Update README
Merge https://github.com/flying-sheep/html5sortable
Update README
Tabs to spaces and fix for options being reset when doing reload.
AngularJS directive.
Update documentation.
Update README.md