Bring telepathy-ring up to 'core CM' status

Submitted by Guillaume Desmottes `@gdesmott`

Assigned to Telepathy bugs list

telepathy-ring is currently living its own live on https://github.com/nemomobile/telepathy-ring

Ideally, it would be great to make it a core part of the Telepathy project which would include:

Move its repo to git.freedesktop.org and create accounts for its current maintainers
Move its bugs to bugs.freedesktop.org
Add a test suite. I started working on this and already submit the simplest bits for review ( https://github.com/nemomobile/telepathy-ring/pull/14 ). I have more unfinished patches in https://github.com/gdesmott/telepathy-ring/commits/tests but they need more work (see my FIXME).
Bump tp-blib deps to the latest pre 1.0 release and make sure we build with deprecations enabled
Port to 1.0