Add links to 1.16 docs and downloads

Author: jvz

src/site/site.xml

@@ -28,6 +28,7 @@
             <item name="Download"        href="https://commons.apache.org/codec/download_codec.cgi"/>
             <item name="Users guide"     href="/userguide.html"/>
             <item name="Javadoc current" href="/apidocs/index.html"/>
+            <item name="Javadoc 1.16"    href="/archives/1.16/apidocs/index.html"/>
             <item name="Javadoc 1.15"    href="/archives/1.15/apidocs/index.html"/>
             <item name="Javadoc 1.14"    href="/archives/1.14/apidocs/index.html"/>
             <item name="Javadoc 1.13"    href="/archives/1.13/apidocs/index.html"/>

src/site/xdoc/index.xml

@@ -72,6 +72,7 @@ The Javadoc API documents are available online:
 </p>
 <ul>
   <li><a href="apidocs/index.html">Javadoc current (git master)</a></li>
+  <li><a href="archives/1.16/apidocs/index.html">Javadoc 1.16</a></li>
   <li><a href="archives/1.15/apidocs/index.html">Javadoc 1.15</a></li>
   <li><a href="archives/1.14/apidocs/index.html">Javadoc 1.14</a></li>
   <li><a href="archives/1.13/apidocs/index.html">Javadoc 1.13</a></li>
@@ -90,7 +91,8 @@ The <a href="scm.html">subversion repository</a> can be
 <!-- ================================================== -->
 <section name="Releases">
 <ul>
-  <li><a href="https://commons.apache.org/codec/download_codec.cgi">Codec 1.15 (mirrors)</a> requires Java 7</li>
+  <li><a href="https://commons.apache.org/codec/download_codec.cgi">Codec 1.16 (mirrors)</a> requires Java 8</li>
+  <li><a href="https://archive.apache.org/dist/commons/codec/">Codec 1.15 (archives)</a> requires Java 7</li>
   <li><a href="https://archive.apache.org/dist/commons/codec/">Codec 1.14 (archives)</a> requires Java 7</li>
   <li><a href="https://archive.apache.org/dist/commons/codec/">Codec 1.13 (archives)</a> requires Java 7</li>
   <li><a href="https://archive.apache.org/dist/commons/codec/">Codec 1.12 (archives)</a> requires Java 7</li>