- Add the possibility to control engines through control names but

- Add the possibility to control engines through control names but
  with arbitrary arguments instead of just a string.
- Change the key loaders to take a UI_METHOD instead of a callback
  function pointer.  NOTE: this breaks binary compatibility with
  earlier versions of OpenSSL [engine].
- Addapt the nCipher code for these new conditions and add a card
  insertion callback.