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/ui/actions/MemberFilterActionGroup.java
*/	
	public boolean hasMemberFilter(int filterProperty) {
		return fFilter.hasFilter(filterProperty);
	}
	
	/**
	 * Saves the state of the filter actions in a memento.
	 * 
	 * @param memento the memento to which the state is saved
	 */
	public void saveState(IMemento memento) {
		memento.putString(TAG_HIDEFIELDS, String.valueOf(hasMemberFilter(FILTER_FIELDS)));
		memento.putString(TAG_HIDESTATIC, String.valueOf(hasMemberFilter(FILTER_STATIC)));
		memento.putString(TAG_HIDENONPUBLIC, String.valueOf(hasMemberFilter(FILTER_NONPUBLIC)));
	}
	
	/**
	 * Restores the state of the filter actions from a memento.
	 * <p>
	 * Note: This method does not refresh the viewer.
	 * </p>
	 * @param memento the memento from which the state is restored
	 */	
	public void restoreState(IMemento memento) {
		setMemberFilters(
			new int[] {FILTER_FIELDS, FILTER_STATIC, FILTER_NONPUBLIC},
			new boolean[] {
				Boolean.valueOf(memento.getString(TAG_HIDEFIELDS)).booleanValue(),
				Boolean.valueOf(memento.getString(TAG_HIDESTATIC)).booleanValue(),
				Boolean.valueOf(memento.getString(TAG_HIDENONPUBLIC)).booleanValue()