feat-use-new-passwd #1095

implements a new password system that includes preferred hash + complexity to automatically rehash on login if needed.

~~This is using argon2i but i can add support for argon2id.~~

now prefers argon2id per comments on #1093

closes #1093

Didn't run the code, only looked at it so far. Couldn't find any obvious mistakes. Will try it on the weekend.

Did some manual testing...

 		hash, err := a.pm.Passwd(password, "")
 		if err != nil {
 			log.WithError(err).Error("error creating password hash")
 			http.Error(w, "Passwrod Creation Failed", http.StatusInternalServerError)

 			// Save upgraded user password
 			if err := s.db.SetUser(username, user); err != nil {
 				ctx.Error = true
 				ctx.Message = s.tr(ctx, "ErrorGetUser")

 			// Save upgraded user password
 			if err := a.db.SetUser(username, user); err != nil {
 				log.WithError(err).Error("error saving user object for user")