Bug 298835 Merge e4 Project Path Variable back into the 3.6 stream
The virtual folder and filters changes are already in 3.6, the project path variable changes in e4 still remains to be merged.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/ide/dialogs/PathVariablesGroup.java
private IResource currentResource = null;
    private final static String PARENT_VARIABLE_NAME = "PARENT"; 
    
	/**
     * Creates a new PathVariablesGroup.
     *
     * @param multiSelect create a multi select tree
     * @param variableType the type of variables that are displayed in 
     * 	the widget group. <code>IResource.FILE</code> and/or <code>IResource.FOLDER</code>
     * 	logically ORed together.
     */
    public PathVariablesGroup(boolean multiSelect, int variableType) {
        this.multiSelect = multiSelect;
        this.variableType = variableType;
        pathVariableManager = ResourcesPlugin.getWorkspace()
                .getPathVariableManager();
        removedVariableNames = new HashSet();
        tempPathVariables = new TreeMap();
        
        initTemporaryState();
    }
    /**
     * Creates a new PathVariablesGroup.
     *
     * @param multiSelect create a multi select tree
     * @param variableType the type of variables that are displayed in 
     * 	the widget group. <code>IResource.FILE</code> and/or <code>IResource.FOLDER</code>
     * 	logically ORed together.
     * @param selectionListener listener notified when the selection changes
     * 	in the variables list.