The enclosed patch implements MI notifications about breakpoint changes.
As other MI notifications, those are emitted only when breakpoint changes
by something that is not a MI command to change a breakpoint. For example,
-break-condition will not cause a breakpoint-changed notification to be
emitted.

This functionality was independently written by Tom and myself, and this
patch merges the patches together. As a side effect, existing breakpoint
observers were modified to take a pointer to breakpoint rather than it,
which eliminates quite some busywork.

Tested on x86 with no regressions. Comments?

- Volodya

-- 
Vladimir Prus
Mentor Graphics
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