Redmine#5986: fix to assume all non-specified return codes are failed
Revert "Retrying SSL_accept and SSL_connect if error.", again.

This reverts commit 39375e1bb04f165d8fe996734fe17eaccc78ca81.

All our code uses *blocking* sockets. We shouldn't have to deal with
fragile polling loops and secondary time-outs with no real reason.

There *is* one case that we get the SSL_ERROR_WANT_READ error even
though our socket is blocking, but I'll comment and cover that one case
with a separate pull request.

Conflicts:
	cf-serverd/tls_server.c
	libcfnet/tls_client.c
Log nice error message in case of recv timeout within OpenSSL.
Assert that the openssl sockets are blocking.

If we ever need to use non-blocking sockets, that need should be
accomodated by creating different API for that. Our current functions
are surprisingly simple (a good thing!) because they don't work for
non-blocking sockets.
Log more appropriate message if interrupted by signal

In addition, reworded a couple of messages in order to not repeat the
"error" word.