Make it much clearer how to enable TLS mode for clients.

Closes #776.

man/mosquitto_pub.1.xml

@@ -90,6 +90,19 @@
 			exit.</para>
 	</refsect1>
 
+	<refsect1>
+		<title>Encrypted Connections</title>
+		<para><command>mosquitto_pub</command> supports TLS encrypted
+			connections. It is strongly recommended that you use an encrypted
+			connection for anything more than the most basic setup.</para>
+		<para>To enable TLS connections when using x509 certificates, one of
+			either <option>--cafile</option> or <option>--capath</option> must
+			be provided as an option.</para>
+		<para>To enable TLS connections when using TLS-PSK, you must use the
+			<option>--psk</option> and the <option>--psk-identity</option>
+			options.</para>
+	</refsect1>
+
 	<refsect1>
 		<title>Options</title>
 		<para>The options below may be given on the command line, but may also

man/mosquitto_sub.1.xml

@@ -97,6 +97,19 @@
 			clean session set to false. </para>
 	</refsect1>
 
+	<refsect1>
+		<title>Encrypted Connections</title>
+		<para><command>mosquitto_pub</command> supports TLS encrypted
+			connections. It is strongly recommended that you use an encrypted
+			connection for anything more than the most basic setup.</para>
+		<para>To enable TLS connections when using x509 certificates, one of
+			either <option>--cafile</option> or <option>--capath</option> must
+			be provided as an option.</para>
+		<para>To enable TLS connections when using TLS-PSK, you must use the
+			<option>--psk</option> and the <option>--psk-identity</option>
+			options.</para>
+	</refsect1>
+
 	<refsect1>
 		<title>Options</title>
 		<para>The options below may be given on the command line, but may also