docs: Update release date

docs/manual.adoc

@@ -2098,7 +2098,7 @@ Because of the differences in document object models, performance considerations
 :!numbered:
 
 [[v1.6]]
-=== v1.6 ^15.04.2015^
+=== v1.6 ^10.04.2015^
 
 Maintenance release. Changes:
 

docs/manual.html

@@ -572,7 +572,7 @@ body.book #toc,body.book #preamble,body.book h1.sect0,body.book .sect1>h2{page-b
 </li>
 <li><a href="#changes">9. Changelog</a>
 <ul class="sectlevel2">
-<li><a href="#v1.6">v1.6 <sup>15.04.2015</sup></a></li>
+<li><a href="#v1.6">v1.6 <sup>10.04.2015</sup></a></li>
 <li><a href="#v1.5">v1.5 <sup>27.11.2014</sup></a></li>
 <li><a href="#v1.4">v1.4 <sup>27.02.2014</sup></a></li>
 <li><a href="#v1.2">v1.2 <sup>1.05.2012</sup></a></li>
@@ -4001,7 +4001,7 @@ If exceptions are disabled, then in the event of parsing failure the query is in
 <h2 id="changes"><a class="anchor" href="#changes"></a>9. Changelog</h2>
 <div class="sectionbody">
 <div class="sect2">
-<h3 id="v1.6"><a class="anchor" href="#v1.6"></a>v1.6 <sup>15.04.2015</sup></h3>
+<h3 id="v1.6"><a class="anchor" href="#v1.6"></a>v1.6 <sup>10.04.2015</sup></h3>
 <div class="paragraph">
 <p>Maintenance release. Changes:</p>
 </div>
@@ -5509,7 +5509,7 @@ If exceptions are disabled, then in the event of parsing failure the query is in
 </div>
 <div id="footer">
 <div id="footer-text">
-Last updated 2015-03-24 20:19:09 PDT
+Last updated 2015-04-10 20:49:27 PDT
 </div>
 </div>
 </body>