Hello there,
Here is a very naive implementation of diagnostics support for camera1394.

Rationale: Firewire cameras are often unstable on Linux. It is really bothersome
to start a demo, launching a bunch of nodes and realizing that the grabbing just
don't work and you have to reset the bus or worse to recover.

It is a simple use of diagnostic_updater::TopicDiagnostic to make sure
that if image_raw publishing rate drops
before a certain rate, it will trigger an error in the diagnostics
topics. On the same idea, it could as well trigger an
error when the initialization fails.

The implementation is untested but it compiles. It would like first to
have feedbacks regarding the patch
before going further.

Thanks,

Attached: path proposal, based on current trunk (r38171).
-- 
Thomas Moulard