PasswordMatch Validator Proposal

[simon-mundy]

Along with NoRecordExists and RecordExists a common workflow is to attach a password-hashing match to form submission for validation.

This packages proposes to:

• Use either a Db\Sql\Select object or a Db\TableGateway to query the submitted value.
• Assume that the value for validation will be pre-hashed to avoid the possibility of plaintext passwords in Db logs.
• Allow a custom hashing mechanism for convenience

[tyrsson]

I would prefer to only allow matching of passwords that have been hashed by the password_hash function as recommended by the php team.