* [NOD-373] Implement Schnorr digital signatures and remove ECDSA (based on code from gcash/bchd)
* [NOD-374] Add new error to list; Update comments.
* [NOD-373] Remove leftovers of verifyMessage RPC command (which was deleted)
* [NOD-373] Remove redundant test, add Schnorr tests, and fix tests where needed
* [NOD-373] Fix tests and remove redundant ones
* [NOD-373] Refactor functions names
* [NOD-373] Remove empty line
* [NOD-373] Fix comments, rename functions to more meaningful names
* [NOD-373] Additional data in nonceRFC6979 should not be nil
* [NOD-373] Refactor function name
* [NOD-373] Add permalinks for links to bchd code