update whatsnew.dox

doc/dox/whatsnew.dox

@@ -118,6 +118,7 @@ Changes, compared to  \ref page_whatsnew_V4_0_0 "v4.0.0" include:
     <li>NEW: Due to addition of JKQTMathText::setFontOptions() and the matchign extension of JKQTMathText::setFontSpecial() (see below) you can now add modifiers like <tt>+BOLD+ITALIC</tt> to any font-name provided to JKQTPlotter and in style INI-files</li>
     <li>NEW: added JKQTPLabelMinBesides and JKQTPLabelMaxBesides to JKQTPLabelPosition, so labels can be set besides the axes</li>
     <li>NEW/REWORKED all functions in JKQTBasePlotter are re-entrant, i.e. different instances can be used from different threads in parallel (although there is some overhead due to shared caches between the threads!). This is demonstrated and discussed in \ref JKQTPlotterMultiThreaded . </li>
+    <li>NEW: NEW allow linear-gradient()... in brush definitions of style.ini-file</li>
   </ul></li>
 
   <li>JKQTMathText:<ul>