* Move key calculation routines into gcr-subject-public-key.c
 * Move creation of SPK from gcr-fingerprint.c into here
 * Implement loading of SPK from PKCS#11 certificates, public keys,
   private keys
 * Add support for parsing SubjectPublicKeyInfo to parser. Generates
   attributes for a CKO_PUBLIC_KEY
 * Fix bugs in DER encoding related to this.
 * More tweaks on testing infrastructure