Dcoument -alpn flag

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

doc/apps/s_client.pod

@@ -95,6 +95,7 @@ B<openssl> B<s_client>
 [B<-rand file(s)>]
 [B<-serverinfo types>]
 [B<-status>]
+[B<-alpn protocols>]
 [B<-nextprotoneg protocols>]
 [B<-ct|noct>]
 [B<-ctlogfile>]
@@ -472,9 +473,13 @@ file.
 sends a certificate status request to the server (OCSP stapling). The server
 response (if any) is printed out.
 
-=item B<-nextprotoneg protocols>
+=item B<-alpn protocols>, B<-nextprotoneg protocols>
 
-enable Next Protocol Negotiation TLS extension and provide a list of
+these flags enable the 
+Enable the Application-Layer Protocol Negotiation or Next Protocol
+Negotiation extension, respectively. ALPN is the IETF standard and
+replaces NPN.
+The B<protocols> list is a
 comma-separated protocol names that the client should advertise
 support for. The list should contain most wanted protocols first.
 Protocol names are printable ASCII strings, for example "http/1.1" or

doc/apps/s_server.pod

@@ -100,6 +100,7 @@ B<openssl> B<s_server>
 [B<-status_verbose>]
 [B<-status_timeout nsec>]
 [B<-status_url url>]
+[B<-alpn protocols>]
 [B<-nextprotoneg protocols>]
 
 =head1 DESCRIPTION
@@ -471,9 +472,13 @@ Sets a fallback responder URL to use if no responder URL is present in the
 server certificate. Without this option an error is returned if the server
 certificate does not contain a responder address.
 
-=item B<-nextprotoneg protocols>
+=item B<-alpn protocols>, B<-nextprotoneg protocols>
 
-Enable Next Protocol Negotiation TLS extension and provide a
+these flags enable the 
+Enable the Application-Layer Protocol Negotiation or Next Protocol
+Negotiation extension, respectively. ALPN is the IETF standard and
+replaces NPN.
+The B<protocols> list is a
 comma-separated list of supported protocol names.
 The list should contain most wanted protocols first.
 Protocol names are printable ASCII strings, for example "http/1.1" or