Notice about WebKitGTK+ unstable DOM API

[Michael Catanzaro <mcatanzaro gnome org>]

Hi distributors,

I want to provide a warning regarding WebKit's unstable DOM bindings
API. This API is subject to API/ABI changes in minor (2.x) release
updates. (It will not intentionally change in micro 2.x.y updates.) If
you follow our recommendation to always update to the latest stable
release -- the only way to get required security updates -- this could
cause problems for applications using the API. We are not aware of any
distros that have been affected by this in the past, but we expect it
to be an issue when upgrading from 2.12 -> 2.14 (or 2.13 if your distro
follows our development releases) as an API used by Epiphany has
changed.

This API is only accessible if WEBKIT_DOM_USE_UNSTABLE_API has been
defined. To our knowledge, the only apps using this API currently are
Epiphany and Yelp. You can avoid potential problems if you simply
rebuild these two applications when updating to new versions of WebKit.
This should ensure your security updates are safe and uneventful.

If we learn that other apps are using this API in the future, we will
let you know here.

Michael