Move bleadperl to 'fail ok' submatrix and add 5.8.1 just because
Only smoke blead-pan on allowed-to-fail runs
Do one poisoned env testrun with a threaded perl
Manpages are of no use on travis
Prevent DBD::Firebird and DBD::InterBase from colliding on same DSN
Changes for 113e8d16 and 64c50e81