fix(moveColumn): account for width of left container when positioning…

… moving

column header.

 Fixes #3417, #3395

src/features/move-columns/js/column-movable.js

@@ -269,6 +269,10 @@
                 var downFn = function( event ){
                   //Setting some variables required for calculations.
                   gridLeft = $scope.grid.element[0].getBoundingClientRect().left;
+                  if ( $scope.grid.hasLeftContainer() ){
+                    gridLeft += $scope.grid.renderContainers.left.header[0].getBoundingClientRect().width;
+                  }
+
                   previousMouseX = event.pageX;
                   totalMouseMovement = 0;
                   rightMoveLimit = gridLeft + $scope.grid.getViewportWidth();