Bug 161401 [Viewers] Tweak ColumnViewer-API
- Rename getRowPart(Point point) => getViewerRow() - Rename getCell(Point point) => getViewerCell() - Rename setViewerColumn(final int columnIndex, ViewerColumn viewer) => setupEditingSupport - Make setupEditingSupport() private no one from external needs to use this API to set the EditingSupport for an ViewerColumn
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/TreeViewer.java
if (updateLabels) {
				if (widget instanceof Tree) {
					((Tree) widget).clearAll(true);
				} else if (widget instanceof TreeItem) {
					((TreeItem) widget).clearAll(true);
				}
			}
			return;
		}
		super.internalRefreshStruct(widget, element, updateLabels);
	}
	/**
	 * Traverses the visible (expanded) part of the tree and updates child
	 * counts.
	 * 
	 * @param widget
	 * @param element
	 * @param updateLabels
	 */
	private void virtualRefreshChildCounts(Widget widget, Object element) {
		if (widget instanceof Tree || ((TreeItem) widget).getExpanded()) {
			
			if (element != null) {
				virtualLazyUpdateChildCount(widget, getChildren(widget).length);
			} else {
				if (widget instanceof Tree) {
					((Tree) widget).setItemCount(0);
				} else {
					((TreeItem) widget).setItemCount(0);
				}