Twit 02 Retrieve user twitter home stream

Creates a generic parser and requester. Performing a request against the REST api now requires the correct pair. 

Example:
To request the twitter android dev stream, the request requires the TwitterObjectRequester (Twitter responds with a JsonObject) and the TweetsHashTagParser to parse the Json object.


I know I mentioned the opposite the other day, but in this case you might want to return here directly the result and then return `null` down there if something wrong happens, that way people don't need to think about why `signedUrl` is outside the scope of the `try` and why is it initialised to `null`

Up to you tho