JShint will be executed with paver run_jshint, which will use a defined set of
directories (likewise defined are directories to ignore). A limit can be imposed
on the total number of violations. Note that this change does NOT include adding
jshint to diff-quality or `paver run_quality`.
This allows developers to pass the `--pdb` flag to paver test commands,
and that flag will be proxied to the `nosetests` command. It's useful
for debugging purposes.
