Improvement: Add hotid on instance

[Rex90]

Right now when you pass hot-id attribute it doesnt get attached to the core instance of the table. This is really useful to have when there are multiple tables on a sheet. I cant check in code but on my local version of ngHandsontable adding this worked:

        if (htSettings.hotId) {
          hot.hotId = htSettings.hotId; // add this line 143
          hotRegisterer.registerInstance(htSettings.hotId, hot);
        }

[Rex90]

In the mean time i created this custom directive

app.directive('hotIdAppend',["hotRegisterer",function(hotRegisterer) {
    return {
        restrict: 'A',
        link: function (scope, element, attr){
            var hotInstance = hotRegisterer.getInstance(attr.hotId);
            hotInstance.hotId = attr.hotId;
        }
    };
}]);