In bio.h rev. 1.39 2018/02/22 16:38:43, jsing@ provided BIO_up_ref(3).

In bio.h rev. 1.39 2018/02/22 16:38:43, jsing@ provided BIO_up_ref(3).
Merge the documentation from OpenSSL, tweaked by me.  While here,
fix the in parts imprecise, in parts incorrect descriptions of
BIO_new(3), BIO_set(3), BIO_free(3), and BIO_free_all(3).