Jul 2014 docs adjustments

Lots of fun stuff! This probably needs review before merging, to make sure I didn't slip up somewhere. 

We should also discuss where to merge it. Once we know whether the changes are good, let me know whether I should rebase onto stable or something. Ideally, I'd like to get these into 2.0, 2.1, and next. 
a subquery is not a string, its a statement (if we use the same semantics we've used elsewhere).