Bug 45062 Don't filter output folder and class files
Create a Java project with source folder src and output folder bin. The bin folder will not be shown in the Packages Explorer. Create a Java project with source folder src and output folder output/bin. The output and bin folders are shown in the Packages Explorer. Implictly filtering out bin is confusing and inconsistent. A better way to do this would be to use a name filter for bin or add "Output folder" to the list of available filters.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/packageview/PackageExplorerPart.java
private PackageExplorerLabelProvider fLabelProvider;	
	
	/* (non-Javadoc)
	 * Method declared on IViewPart.
	 */
	private boolean fLinkingEnabled;
	public void init(IViewSite site, IMemento memento) throws PartInitException {
		super.init(site, memento);
		fMemento= memento;
		restoreLayoutState(memento);
	}
	private void restoreLayoutState(IMemento memento) {
		Integer state= null;
		if (memento != null)
			state= memento.getInteger(TAG_LAYOUT);
		
		if(state == null) {
			IPreferenceStore store= JavaPlugin.getDefault().getPreferenceStore();
			state= new Integer(store.getInt(TAG_LAYOUT));
		}
		if (state.intValue() == FLAT_LAYOUT)
			fIsCurrentLayoutFlat= true;
		else if (state.intValue() == HIERARCHICAL_LAYOUT)
			fIsCurrentLayoutFlat= false;
		else
			fIsCurrentLayoutFlat= true;
	}
	
	/**
	 * Returns the package explorer part of the active perspective. If