work on divert-to-key and other keyring stuff

- allow modifySecretKeyRing operation without passphrase, but a only
  restricted subset of operations (ie, s2k strip/divert)
- pass byte array with serial number to key edit operation to initialize
  divert-to-card key
- update spongycastle to support serial numbers in iv for divert-to-card

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/EditKeyFragment.java

@@ -481,7 +481,7 @@ public class EditKeyFragment extends LoaderFragment implements
                     case EditSubkeyDialogFragment.MESSAGE_STRIP:
                         SubkeyChange change = mSaveKeyringParcel.getSubkeyChange(keyId);
                         if (change == null) {
-                            mSaveKeyringParcel.mChangeSubKeys.add(new SubkeyChange(keyId, true, false));
+                            mSaveKeyringParcel.mChangeSubKeys.add(new SubkeyChange(keyId, true, null));
                             break;
                         }
                         // toggle