Bug 25827 Disposing of MemberFilterActionGroup
Build 2.0.2 and 2.1 When investigating an editor memory leak PR we found out that this group has a dispose method which is never called. When we then called from the editor it throw an exeption (viewer was disposed). Don't know if the group really needs dispose() if so it should get called.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/JavaOutlinePage.java
public boolean isDeleted(Object o) {
					return false;
				}
				
				public void dispose() {
					if (fListener != null) {
						JavaCore.removeElementChangedListener(fListener);
						fListener= null;
					}		
				}
				
				/*
				 * @see IContentProvider#inputChanged(Viewer, Object, Object)
				 */
				public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
					boolean isCU= (newInput instanceof ICompilationUnit);
									
					if (isCU && fListener == null) {
						fListener= new ElementChangedListener();
						JavaCore.addElementChangedListener(fListener);
					} else if (!isCU && fListener != null) {
						JavaCore.removeElementChangedListener(fListener);
						fListener= null;
					}
				}
			};
			
			
			class JavaOutlineViewer extends TreeViewer {