encoding/json: change DisableHTMLEscaping to SetEscapeHTML
DisableHTMLEscaping is now SetEscapeHTML, allowing the escaping
to be toggled, not just disabled. This API is new for Go 1.7,
so there are no compatibility concerns (quite the opposite,
the point is to fix the API before we commit to it in Go 1.7).
Change-Id: I96b9f8f169a9c44995b8a157a626eb62d0b6dea7
Reviewed-on: https://go-review.googlesource.com/23293 Reviewed-by: Ian Lance Taylor <iant@golang.org> Reviewed-by: Andrew Gerrand <adg@golang.org>