GitHub #319: Improved error message for incompatible exec data files.

In case of incompatible execution data formats read from another JaCoCo
version ExecutionDataReader.read() now throws a
IncompatibleExecDataVersionException with a better error message.
diff --git a/org.jacoco.doc/docroot/doc/changes.html b/org.jacoco.doc/docroot/doc/changes.html
index a768e7b..ddc9355 100644
--- a/org.jacoco.doc/docroot/doc/changes.html
+++ b/org.jacoco.doc/docroot/doc/changes.html
@@ -20,12 +20,27 @@
 
 <h2>Snapshot Build @qualified.bundle.version@ (@build.date@)</h2>
 
+<h3>New Features</h3>
+<ul>
+  <li>Improved error message in case of incompatible execution data files.
+      (GitHub <a href="https://github.com/jacoco/jacoco/issues/319">#319</a>).</li>
+</ul>
+
+
 <h3>Fixed Bugs</h3>
 <ul>
   <li>Fix <code>MBeanClient</code> example
       (GitHub <a href="https://github.com/jacoco/jacoco/issues/333">#333</a>).</li>
 </ul>
 
+<h3>API Changes</h3>
+<ul>
+  <li>In case of incompatible execution data formats read from another JaCoCo
+  version <code>ExecutionDataReader.read()</code> now throws a 
+  <code>IncompatibleExecDataVersionException</code>.</li>
+</ul>
+
+
 <h2>Release 0.7.5 (2015/05/24)</h2>
 
 <h3>New Features</h3>