Changes in version 2.25.4 are:
* Half way through refactoring of PKCS#11 support.
* Add crypto support to gp11 library.
* gp11 library is now by and large thread-safe.
* Add modular ssh-store, roots and rpc-layer PKCS#11 components.
* Beginnings of a PKCS#11 based ssh-agent.
* Transactional storage of PKCS#11 objects.
* Add auto-authenticate support in GP11 library, which greatlty 
  simplifies figuring out when to provide passwords.
* Fix initialization problems which prevented SSH agent from setting
  environment variables properly [Yanko Kaneti]
* Translation fixes [Gabor Kelemen]