Improved pagination support

[chriskapp]

Many APIs have some kind of paged collection response where the initial request only returns a subset of the complete collection i.e.

{
    "totalEntries": 1024,
    "itemsPerPage": 16,
    "startIndex": 32,
    "entries": [{ ... }]
}

A user often needs to go through this pagination to get more entries. It would be great if our client SDK would provide support for such a pagination by providing an iterator which automatically goes through each page so that the user does not need to do this manually. The spec needs to contain the information that the response is a collection and how the query parameters are named to go through each page.