[Various] obsoleting the annotate level 2 interface

[Arnaud Charlet]

> And the missing features are...?

I've stated them at least 3 times in this thread (which I assume is archived),
but here there are again:

- stability in the MI interface
- ability to provide a user console with the CLI syntax

Note that we haven't started implemented support for MI in GVD, so these are
really the two obvious features. Others may appear when we start implementing
the real support.

What are the gdb front-ends currently using MI ? It would be interesting to
see the state of these front-ends and the problems encountered.

Arno