This patch fixes the build system from almost insane to
something more digestible.
Replaces intereactive questions with uname checks, gets
rid of non-standard __ppc__ macro, gets libcrypto to
use standard <endian.h> facility for endianess check.
Add "set -e" in a few places.
It's still not complete and the thing won't yet build
on my system (debian sid), but it's an improvement.