Clarify behaviour of SSL_write() by mentioning SSL_MODE_ENABLE_PARTIAL_WRITE flag as discussed on the mailing list.
Clarify behaviour of SSL_write() by mentioning SSL_MODE_ENABLE_PARTIAL_WRITE
flag as discussed on the mailing list.

openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl