openssh 3.1p1 linking problem

[Noah Friedman]

It's recommended that recent versions of openssl be built only as static
libraries because the ABIs are not yet stable (esp. the `engine'
component).  However, the library still uses dlopen.

Linking openssh will therefore fail unless linking against -ldl explicitly
along with -lcrypto.  It should be harmless to do so when linking
dynamically.

Also, it would be useful if the configure script for openssh would check
for the minimum version of openssl required.  Version 0.9.5 did not define
some functions that openssh wanted; I had to upgrade to 0.9.6.