Note BUF_MEM_grow() consistency fix.

         *) applies to 0.9.6a/0.9.6b/0.9.6c and 0.9.7

         +) applies to 0.9.7 only

  +) Make BUF_MEM_grow() behaviour more consistent: Initialise to zero

     additional bytes when new memory had to be allocated, not just

     when reusing an existing buffer.

     [Bodo Moeller]

  *) Disable caching in BIO_gethostbyname(), directly use gethostbyname()

     instead.  BIO_gethostbyname() does not know what timeouts are

     appropriate, so entries would stay in cache even when they hade

     appropriate, so entries would stay in cache even when they have

     become invalid.

     [Bodo Moeller; problem pointed out by Rich Salz <rsalz@zolera.com>