Add Option to Fetch Full States

[NotAFile]

Currently, there seems to be no way of fetching state with the default Syncer. You would need to essentially write your own Syncer.

[NotAFile]

Correction: you can get state events manually with code like this:

	content := struct {
		Name string `json:"name"`
	}{}

	client.StateEvent(rm.ID, "m.room.name", "", &content)

but it's not very elegant and you basically need to do the decoding yourself.