Reviewed-by: NRichard Levitte <levitte@openssl.org>

Fix some code examples, trailing whitespace
Fix TBA sections in verify, remove others.
Remove empty sections
Use Mixed Case not ALL CAPS in head2
Enhance doc-nits script.
Remove extra =cut line
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Add doc-nit-check to help find future issues.
Make podchecker be almost clean.
Remove trailing whitespace.
Tab expansion
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Reviewed-by: NRichard Levitte <levitte@openssl.org>

Reported-by: Claus Assmann
Reviewed-by: NRich Salz <rsalz@openssl.org>

Also tweak some of the code in demos/bio, to enable interactive
testing of BIO_s_accept's use of SSL_dup.  Changed the sconnect
client to authenticate the server, which now exercises the new
SSL_set1_host() function.
Reviewed-by: NRichard Levitte <levitte@openssl.org>