minor change to CLA in readme.
minor refactor. remove useless args.
Revert "see #302. remove all obsolete features. keep things easy to revert."

This reverts commit f9c90b0cdb15d6a3ef087b79364b979fb8ef81bb.

Revert "Fix test cases. Since we have removed the headerPrefix option. There"

This reverts commit 509b284c7cc09232562c89a91453797ab88fd73f.