Merge pull request #390 from SenecaCDOT-BigBlueButton/slide-zoom-change-presenter-sync

fixed 'zoom slider won't update value after presenter have changed'

bigbluebutton-client/src/org/bigbluebutton/modules/present/ui/views/SlideView.mxml

@@ -357,6 +357,9 @@ with BigBlueButton; if not, see <http://www.gnu.org/licenses/>.
 			}
 			
       private function becomePresenter():void {
+        // need to calculate slide zoom percantage left by a previous presenter
+        zoomPercentage = (SlideViewModel.HUNDRED_PERCENT / slideModel.viewedRegionH) * SlideViewModel.HUNDRED_PERCENT;
+
         addEventListener(MouseEvent.MOUSE_WHEEL, onMouseWheelZoomEvent);
         slideLoader.addEventListener(MouseEvent.MOUSE_DOWN, onMouseDown);
         slideLoader.addEventListener(MouseEvent.MOUSE_UP, onMouseUp);