Wm notes 1.15.0

Pinging @mglukhovsky (and @larkost if he wants to check my checking on pull requests and issues).
This doesn't explain what this was actually fixing, which I believe was that r.literal was being rejected with certain convoluted values on the server (directly using the $reql_type$ as LITERAL).

I might say "Fixed a bug for `r.literal` corner cases" since it's extremely unlikely anyone would run into this.