Here's a stab at a consolidation of the SSL detection heuristics into
configure. Source files aren't changed by this patch, except for setup.h and
the various config*.h files. Within the configure script, OPENSSL_ENABLED is
used to determine if SSL is being used or not, and outside configure,
USE_SSLEAY means the same thing; this could be even further unified some day.
Now, when SSL is not detected, configure skips the various checks that are
dependent on SSL, speeding up the configure process and avoiding complications
with cross compiles. I also updated all the architecture- specific config
files I could see, but I couldn't test them.
