feat(core): raw responses

feat(problems): customizable errors key

feat(router): redirect trailing slashes

feat(router): add support for wildcards

fix(problems): details now get defaulted even if no error & better er…

…ror message

feat(problems): lowercased error stack

feat(problems): added error stack traces

feat(docs): documented a few more stuff

feat(docs): readme documentation

fix(router): fixes middleware order