Add angular-ui-sortable, updated PR

Downloaded from: [Angular UI-Sortable Repo](https://github.com/angular-ui/ui-sortable)

 - [v0.12.8 Release](https://github.com/angular-ui/ui-sortable/releases/tag/v0.12.8)


PS
Did as instructed using `git commit --amend` and `git push --force` but previous PR didn't seem to update.