Make only 1 server requests for updates/pushes

[Arthur Valadares]

We are doing 2 requests at every pull: one for tracked, one for updates. This means two roundtrips to the server. We should bundle them in one call. @lordnahor, opinion?
Update: Push is also sending one request per type

[crista]

There should be only one request per pull and one request per push.

[Arthur Valadares]

I just noticed that our push is also doing 1 request per type. I am modifying it to be just one call as well