uncaught exception test using new api
Client constructor throws exception when url param is missing
Trace diff report's sub name shoudn't include a newline
typo

Lead to a bug where the trace diff report would have the package and subroutine
as giant integers.
fix trace diff report
trace diff test working with new api
test uses new api
stack test uses new api
fix 'Useless use of a variable in void context' warnings
Remove unneeded modules
Relax tests checking for END blocks

We're about to remove Devel::hdb::Response, which will change which modules
are loaded.  I couldn't get the test program's END block to reliably fire
when expected, but it should still be true that _some_ END block will fire.
Remove Devel::hdb::Response

Not needed with the new API
Implement the root route