fix(bench): Results of first trial ignored
refactor(hooks): Overload kwargs to pass info instead of using req.ext
fix(Response): Do not return duplicate headers
refactor(bench): Use defaultdict
test(Request): Setting a header overwrites previous value for that header. Fixes #80
refactor(Response): Change header attributes to properties. Fixes #84
feat: Compile modules with Cython if available. Closes #29