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

Inspired by the lazy-loading chase in 524343a9

Skip the test entirely on 5.8 - it is becoming too difficult to predict
extra dependency load order
Tweak timing of t/zzzzzzz_perl_perf_bug.t - we started getting false positives

http://www.cpantesters.org/cpan/report/356dd340-9de0-11e2-9265-e31b922ed931
http://www.cpantesters.org/cpan/report/2e2063f1-6bf4-1014-817e-b9974151da38

Not considering dropping the test because... well it is a good test ;)
Escape more frames when determining carp/throw_exception originator

Augments 5e0e5426b