Debugger/CDB: Fix stack view when attaching to crashed app.

The timer for event-delivery time-out checking when attaching to a
crashed process in the case of not being spawned by the handler
(such as via single-application remote command) triggered too
early. Add a 'moduleLoaded()' signal to CoreEngine and trigger
from there (due to lack of a proper "engine up/attached"
notification.
Emit moduleLoaded() from the first timed-out debug event handler when
modules no longer change.
Reviewed-by: Robert Loehning <robert.loehning@nokia.com>