prepare 3.5

CHANGELOG.txt

-3.5.0 (Work-in-progress): generalized Trace operator on non-conforming meshes;
-new Errf function; source code reorganization.
+3.5.0 (May 13, 2022): generalized Trace operator on non-conforming meshes; new
+Errf function; source code reorganization.
 
 3.4.0 (September 23, 2021): new Min and Max functions on constants (at parse
 time); fixed regression in trees of edges in 2D; added support for non-ASCII

doc/getdp.html

@@ -117,13 +117,13 @@ Public License (GPL)</a>:
 <ul>
   <li>
     <div class="highlight">
-      Current stable release (version 3.4.0, 23 September 2021):
+      Current stable release (version 3.5.0, 13 May 2022):
       <ul>
         <li>Download GetDP for
-          <a href="bin/Windows/getdp-3.4.0-Windows64c.zip">Windows</a>,
-          <a href="bin/Linux/getdp-3.4.0-Linux64c.tgz">Linux</a> or
-          <a href="bin/MacOSX/getdp-3.4.0-MacOSXc.tgz">macOS</a> <a href="#1"><sup>*</sup></a>
-        <li>Download the <a href="src/getdp-3.4.0-source.tgz">source code</a>
+          <a href="bin/Windows/getdp-3.5.0-Windows64c.zip">Windows</a>,
+          <a href="bin/Linux/getdp-3.5.0-Linux64c.tgz">Linux</a> or
+          <a href="bin/MacOSX/getdp-3.5.0-MacOSXc.tgz">macOS</a> <a href="#1"><sup>*</sup></a>
+        <li>Download the <a href="src/getdp-3.5.0-source.tgz">source code</a>
       </ul>
     </div>
   <li>Development version: