File usage.txt artifact 584fd1a98e part of check-in 712876ec1c

::pki::pkcs11::loadmodule <filename>                       -> handle
::pki::pkcs11::unloadmodule <handle>                       -> true/false
::pki::pkcs11::listslots  <handle>                         -> list: slotId label flags
::pki::pkcs11::listcerts  <handle> <slotId>                -> list: keylist
::pki::pkcs11::encrypt <mode> <input> <keylist>            -> data
::pki::pkcs11::decrypt <mode> <input> <keylist>            -> data
::pki::pkcs11::login <handle> <slotId> <password>          -> true/false
::pki::pkcs11::logout <handle> <slotId>                    -> true/false