remove tls_reset(3) from the NAME, SYNOPSIS, and HISTORY sections
because it is documented in the separate tls_client(3) manual page

Group tls_{handshake,read,write,close}() return values documentation.

Move the documentation for tls_error() down so that both the special return
values for tls_{handshake,read,write,close}() direct

Group tls_{handshake,read,write,close}() return values documentation.

Move the documentation for tls_error() down so that both the special return
values for tls_{handshake,read,write,close}() directly follow the standard
return values for the same functions.

Prompted by deraadt@.

ok deraadt@ schwarze@

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tls_read() & tls_write() return 4 possible values: TLS_WANT_POLLOUT,
TLS_WANT_POLLIN, -1, or 0. After handling the first two, check for -1
rather than vaguely "< 0".
ok jsing

fix examples (libtls uses its own error reporting mechanism)

okay tb@

document tls_config_error(3) RETURN VALUES, improve what is said
about tls_error(3), and warn about some traps;
OK jmc@

add HISTORY and AUTHORS

Fix Copyright notices; ok beck@ jsing@ tedu@

split the tls_init(3) that had grown fat to allow healthy future growth;
suggested by jsing@; "i would just chuck it in" jmc@