Update to 1.960
    
    - New upstream release 1.960
      - Only documentation enhancements:
        - Clarify with text and example code, that within event loops not only
          select/poll should be used, but also pending has to be called
        - Better introduction into SSL; at least mention anonymous authentication as
          something you don't want and should take care with the right cipher
        - Make it more clear that it's better not to change the cipher list unless
          you really know what you're doing
    - Adopt upstream's versioning scheme