AngularJS-version of add prefix page

Created an AngularJS-version of the add prefix page. Links to it has been added to the prefix list (to allocate a prefix from a prefix) and the pool list (to allocate a prefix from a pool). Manual assignment is also supported, but there is no link to it so far.

It's still missing some of the flashy features such as scrolling to next relevant part of the page and animated background colors for highlighting.
We don't have any prefix edit functionality at this point, but when we do, I think it's important that we don't need to redefine all the prefix attributes again, like we do here. We need fewer places where we list attributes, not more ;)
I'm only mentioning this as the controller is called PrefixAddController...