docs: document socket.unix and socket.serial, fix stale/missing API referencesdocs/pre-release-audit

Pre-release documentation audit against master. Adds the two fully
undocumented modules and closes gaps found by diffing every docs/*.html
page against its corresponding source:

- New docs/unix.html and docs/serial.html (socket.unix stream/dgram and
  socket.serial were never documented), linked from index.html,
  introduction.html, socket.html and reference.html. serial.html notes
  the current lack of a baud/parity/flow-control API and includes an
  os.execute+stty workaround example. Both note Windows is unsupported.
- socket.html: document headers.setcanonic, point to unix/serial modules.
- tcp.html: document getfamily, setpeername/setsockname aliases.
- udp.html: document getfamily, getfd/setfd, dirty; document the
  ipv6-multicast-hops/ipv6-unicast-hops aliasing as current (known-buggy)
  behavior rather than the originally intended semantics.
- http.html: correct redirect text (301/302/303/307/308, was 301/302
  only); document MAXHEADERLINE/MAXHEADERSIZE.
- dns.html: document getnameinfo.
- ltn12.html: document source.rewind and BLOCKSIZE.
- installation.html: fix stale "LuaSocket 3.0" sample output to 3.1.0.
- reference.html: index every anchor added above plus new Unix/Serial
  blocks.

1 files changed, 43 insertions, 0 deletions

diff --git a/docs/tcp.html b/docs/tcp.html
index 715d28f..580bdcf 100644
--- a/docs/tcp.html
+++ b/docs/tcp.html
@@ -196,6 +196,25 @@ Note: <b>This is an internal method, use at your own risk.</b>
 </p>
 
 
+<!-- getfamily +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ -->
+
+<p class="name" id="getfamily">
+master:<b>getfamily()</b><br>
+client:<b>getfamily()</b><br>
+server:<b>getfamily()</b>
+</p>
+
+<p class="description">
+Returns the family of the underlying socket, as chosen when the object was
+created by <a href="socket.html#connect"><tt>socket.tcp</tt></a>,
+<a href="#socket.tcp4"><tt>socket.tcp4</tt></a> or
+<a href="#socket.tcp6"><tt>socket.tcp6</tt></a>.
+</p>
+
+<p class="return">
+The string "<tt>inet4</tt>" or "<tt>inet6</tt>".
+</p>
+
 <!-- getfd +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ -->
 
 <p class="name" id="getfd">
@@ -651,6 +670,30 @@ This is the default mode;</li>
 This function returns 1.
 </p>
 
+<!-- setpeername +++++++++++++++++++++++++++++++++++++++++++++++++++++++ -->
+
+<p class="name" id="setpeername">
+master:<b>setpeername(</b>address, port<b>)</b>
+</p>
+
+<p class="description">
+Alias for <a href="#connect"><tt>connect</tt></a>, kept for naming symmetry
+with <a href="udp.html#setpeername"><tt>udp:setpeername</tt></a> and with
+<a href="#getpeername"><tt>getpeername</tt></a>.
+</p>
+
+<!-- setsockname +++++++++++++++++++++++++++++++++++++++++++++++++++++++ -->
+
+<p class="name" id="setsockname">
+master:<b>setsockname(</b>address, port<b>)</b>
+</p>
+
+<p class="description">
+Alias for <a href="#bind"><tt>bind</tt></a>, kept for naming symmetry
+with <a href="udp.html#setsockname"><tt>udp:setsockname</tt></a> and with
+<a href="#getsockname"><tt>getsockname</tt></a>.
+</p>
+
 <!-- setfd +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ -->
 
 <p class="name" id="setfd">