A salt type algorithm should be inferred if -S argument is supplied

There is currently a binding between the -S and -R arguments in the commandline client. The user guide states:

• -R [OPTIONAL] The algorithm of checksum to request in the response from the pillars. Allowed values are: MD5, SHA1, SHA256, SHA384, SHA512. If using a salt, prefix the listed types with HMAC_, eg. HMAC_MD5.
• -S [OPTIONAL] The salt of checksum to request in the response. Requires the -R ChecksumType (algorithm) argument with a salt type algorithm.

This could be simplified by just accepting the algorithm types MD5, SHA1, SHA256, SHA384, SHA512, and let the cmd client automatically update these to the salted types if a -S argument is supplied.