Adding a basic paging support

[giulio1979]

I added 2 important things:

http.response.offset.pointer

The parameter tells the system which offsets should be captured from the root document.

http.offset.nextpage

this tells the connector which parameter holds the next page offset so it will trigger and offset update and call again the API.

There is a new field added to the offset, a "nice to have" last call timestamp so you can use it in the next call.