- (djm) autoconf hacking:

 - (djm) autoconf hacking:
   - We don't support --without-zlib currently, so don't allow it.
   - Rework cryptographic random number support detection. We now detect
     whether OpenSSL seeds itself. If it does, then we don't bother with
     the ssh-rand-helper program. You can force the use of ssh-rand-helper
     using the --with-rand-helper configure argument
   - Simplify and clean up ssh-rand-helper configuration