Exclude DBICTest namespace from stacktraces
Fix incorrect warning/exception originator

Until now we would report the second to last function as the
exception originator, whereas we need to report the first after
skipping the usual suspects of throw_exception etc
Escape more frames when determining carp/throw_exception originator

Augments 5e0e5426b
More robust tests of dependency lazy-loading and delay of more req loads

Inspired by the lazy-loading chase in 723f25e0

Skip the test entirely on 5.8 - it is becoming too difficult to predict
extra dependency load order
Self-cleaning is not yet entirely stable - back it out for the time being

As a side-effect resolves RT#86267
remove DBIC specific tests
failed carp unique test
use new method name for skipping frames (see #1)
rename to Carp::Skip