Use maps for and improve options

The type option has been removed. The transport and protocols
options can be used in its place.

The transport_opts option can be used to specify transport
options.

The http_opts and spdy_opts options can be used to specify
protocol specific options.

The keepalive option is now a protocol specific option.

Defaults depending on the port number have changed. Now only
port 443 uses ssl by default, other ports use tcp.

1 files changed, 16 insertions, 8 deletions

diff --git a/doc/src/guide/connect.asciidoc b/doc/src/guide/connect.asciidoc
index e1ad56e..e2bcaa7 100644
--- a/doc/src/guide/connect.asciidoc
+++ b/doc/src/guide/connect.asciidoc
@@ -33,16 +33,24 @@ The `gun:open/{2,3}` function must be used to open a connection.
 [source,erlang]
 {ok, ConnPid} = gun:open("example.org", 443).
 
-@todo open/3
-@todo make opts a map
+If the port given is 443, Gun will attempt to connect using
+SSL. The protocol will be selected automatically using the
+NPN extension for TLS. By default Gun supports SPDY/3.1,
+SPDY/3 and HTTP/1.1 when connecting using SSL.
 
-If the port given is 80, Gun will attempt to connect using
-TCP and use the HTTP/1.1 protocol. For any other port, TLS
-will be used. The NPN extension for TLS allows Gun to select
-SPDY automatically if the server supports it. Otherwise,
-HTTP/1.1 will be used.
+For any other port, Gun will attempt to connect using TCP
+and will use the HTTP/1.1 protocol.
 
-@todo more about defaults
+The transport and protocol used can be overriden using
+options. The manual documents all available options.
+
+Options can be provided as a third argument, and take the
+form of a map.
+
+.Opening an SSL connection to example.org on port 8443
+
+[source,erlang]
+{ok, ConnPid} = gun:open("example.org", 8443, #{transport=>ssl}).
 
 === Monitoring the connection process