SortInfo - executed twice on subscribe

If you are using `sortInfo` it will be executed twice in code:

``` javascript
self.sortData = function (col, direction) {
// if external sorting is being used, do nothing.
self.isSorting = true;
self.sortInfo({ // this is causing first execution
column: col,
direction: direction
});
self.clearSortingData(col);
if(!self.config.useExternalSorting){
window.kg.sortService.Sort(self.sortInfo.peek(), self.sortedData);
} else {
self.config.sortInfo(self.sortInfo.peek()); // this second one
}
self.lastSortedColumn = col;
self.isSorting = false;
};
```

solution is quite straight forward, delay `self.sortInfo` change

will try to do pull request but I don't have access to git from my work :(

Start by locating the sortData function shown in the issue and trace the sortInfo subscription callbacks. Confirm that changing sortInfo causes two executions, then defer the change so subscription handling occurs once. Verify that both internal and external sorting still behave correctly.

Written by the indexing model from the issue text.