Dropdown element as Breadcrumb step

[flaviocolonnascytl]

In my team we were facing a limitation about adding a dropdown with ui-sref links inside the breadcrumb html. We achieved the goal to inject custom HTML, as described in the README, using the $breadcrumbProvider options. But we weren't able to create the links for the dropdown like ncyBreadcrumbLink without touching the code of the library. So, we had to add a small code in order to map the links, coming from custom $state options, with the ui-router. The solution is working but we would like to have it in the library itself instead of having a dirty copy of it. We think it is a nice solution for modern breadcrumbs.