Added separate templates for Aquabrowser and Summon

Each item in the results list (shortrecords) has it's own template, depending on which API has been specified. Currently, we are still using the predefined models to populate the templates. This will change to dynamic models where all the retrieved metadata will be stored (so we will not be making a manual selection of properties any longer). This will allow us to generate format-specific templates, populated by the given metadata.
General comment on this `getContent` function. It took me a while to get my head round it, I feel like it's a bit on the long side and it does quite a bit. I'd suggest applying the [extract method](http://refactoring.com/catalog/extractMethod.html) refactoring several times to break it up into bite sized chunks which can be understood in isolation. For example, you could make the two sides of the `if (!_.isEmpty(req.query))` separate top level methods on the ResourcesController class.

I'd also break out the `_renderItemsTemplate` and `_renderItemTemplate` functions to not be inside `getContent`. In doing so you'll need to define explicitly what their arguments are rather than relying on variables from several nested closures which is hard to keep track of.

I'd also reduce the responsibilities of `_renderItemTemplate`. Currently it's responsible for:

* Rendering an item's template
* Rendering all the items if there are no items left
* Rendering the next item if there's another one
* Also, but less importantly:
** Modifying the `items` array by removing the first item
** Modifying the `templates` array by adding rendered items

Ideally it'd be responsible for just one of these.

If I was you I'd have `_renderItemTemplate` _just_ render the item, nothing else. As a top level function.
Have a separate function responsible for iterating items, calling the simplified `_renderItemTemplate` on each one. Once you do this you'll find that you're just doing a map(), albeit an asynchronous one because of the async `res.render`. You can find [library implementations of async map](https://github.com/caolan/async) which you could use if you'd like, or you could implement it yourself.

Finally, in the callback from rendering all the items you can call the (now top level) `_renderItemsTemplate`.

If you do all this you'll reduce the levels of nesting, reduce the responsibilities and reduce the length of each function. Should make it easier to follow. Hope this makes sense.