[Telepathy] Folks upcoming API break and policy

[Travis Reitter]

In Folks, we're planning to coalesce all our remaining planned API
breaks into the next release to minimize their impact. After this point,
API breaks should be very rare (if ever). Every 0.x.y series, where x is
an even number, will continue to be API- and ABI-stable.

The only planned break is:
bgo#650414 - Need better APIs to handle image data

As usual, we'll generate patches for Empathy, QtFolks, and Gnome
Contacts before including this change in a release.

Regards,
-Travis