Merge pull request #813 from fredg02/JENKINS-10184

[FIXED JENKINS-10184] wrong timestamps in build timeline.

I'm going to just merge this in for now and welcome anyone who finds the proper way to do this.

core/src/main/resources/hudson/model/BuildTimelineWidget/control.jelly

@@ -39,7 +39,7 @@ THE SOFTWARE.
   
   <script>
     <j:invokeStatic var="tz" className="java.util.TimeZone" method="getDefault"/>
-    var tz = ${tz.rawOffset / 3600000};
+    var tz = ${(tz.rawOffset + tz.DSTSavings) / 3600000};
     var tl = null;
     <![CDATA[
     function doLoad() {