Sync angular-kendo changes, update grunt, fix toDataSource error

Updated packages.json to correctly state dependencies required.

Merged changes from ./js/angular-kendo.js to ./angular-kendo.js.

Removed unreferenced file ./js/angular-kendo.js

Removed unneeded throw error in toDataSource. By throwing an exception when source is initiall null/undefined, then $scope.$watch is never called and directive is not updated when the binding source is later set.

Rebuilt angular-kendo.min.js via grunt.