HTTP context header (fix #1053)

Author: vrana

language/context/http.xml

@@ -49,6 +49,13 @@
        Thus it is not recommended to set a <literal>Host:</literal> header,
        if <parameter>follow_location</parameter> is enabled.
       </para>
+      <para>
+       String value should be <literal>Key: value</literal> pairs delimited by
+       <literal>\r\n</literal>, e.g.
+       <literal>"Content-Type: application/json\r\nConnection: close"</literal>.
+       Array value should be a list of <literal>Key: value</literal> pairs, e.g.
+       <literal>["Content-Type: application/json", "Connection: close"]</literal>.
+      </para>
      </listitem>
     </varlistentry>
     <varlistentry xml:id="context.http.user-agent">