Bug 4373 Packages View - double clich doesn't expand two hiearchy levels
- enable: Show CU children in packages view - double click on CU observe: only one level gets expanded - now expand a node by clicking on the + observe: two levels get expanded
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/packageview/PackageExplorerPart.java
TreeViewer getViewer() {
		return fViewer;
	}
	
	/**
 	 * Returns the pattern filter for this view.
 	 * @return the pattern filter
 	 */
	JavaElementPatternFilter getPatternFilter() {
		return fPatternFilter;
	}
	
	/**
 	 * Returns the library filter for this view.
 	 * @return the library filter
 	 */
	LibraryFilter getLibraryFilter() {
		return fLibraryFilter;
	}
	/**
 	 * Returns the Binary filter for this view.
 	 * @return the binary filter
 	 */
	BinaryProjectFilter getBinaryFilter() {
		return fBinaryFilter;
	}
	void restoreFilters() {
		IMemento filtersMem= fMemento.getChild(TAG_FILTERS);
		if(filtersMem != null) {	
			IMemento children[]= filtersMem.getChildren(TAG_FILTER);