Password Hashing with SHA256 and SHA512

- "passwordType" can be added to conf.json to use a hash other than md5.
- Options for passwordType : md5, sha256, sha512. md5 is default.
- Superuser will still be allowed to use MD5 passwords regardless of the "passwordType" selected in conf.json.
- To add salt to your SHA512 accompany the "passwordType":"sha512" with "passwordSalt":"". Fill it with your favorite salty secret.