```
hxtool request-create --subject=... \
--generate-key=... \
--key-bits=... \
--key=STORE \
store
```
wants to generate a key, store it in the location specified by the --key
argument, then read it back, then generate the CSR, and store it in
`store`.
But it didn't work because for generating a key this really wants the
`--key` argument to be a file path into which a raw DER-encoded RSA key
will be written (only RSA is supported, ay!), but for reading the key
back it uses `hx509_certs_init()`, which wants `TYPE:name` keystore
specification. A deadly embrace.
Now that we have improved libhx509 functionality for reading/writing
private keys from/to PEM files we use this functionality and require a
store type in the `--key=STORE` argument.
005ba36b83