I2CP:

- Verify crypto key pair in LS
 - Verfiy same dest as before in LS
Router: Don't try to use an unavailable sig type for the router,
   even if it's the default
RouterInfo: Work around unsupported raw signatures for
   RI Ed25519 sig type

core/java/src/net/i2p/data/PrivateKey.java

@@ -50,6 +50,7 @@ public class PrivateKey extends SimpleDataStructure {
     /** derives a new PublicKey object derived from the secret contents
      * of this PrivateKey
      * @return a PublicKey object
+     * @throws IllegalArgumentException on bad key
      */
     public PublicKey toPublic() {
         return KeyGenerator.getPublicKey(this);