RT3234: disable compression

CRIME protection: disable compression by default, even if OpenSSL is
compiled with zlib enabled. Applications can still enable compression by
calling SSL_CTX_clear_options(ctx, SSL_OP_NO_COMPRESSION), or by using
the SSL_CONF library to configure compression. SSL_CONF continues to
work as before:

SSL_CONF_cmd(ctx, "Options", "Compression") enables compression.

SSL_CONF_cmd(ctx, "Options", "-Compression") disables compression (now
no-op by default).

The command-line switch has changed from -no_comp to -comp.

Reviewed-by: Rich Salz <rsalz@openssl.org>