Bug 323489 [KeyBindings] Reduce memory footprint of BindingManager
bundles/org.eclipse.jface/src/org/eclipse/jface/bindings/BindingManager.java
* The scheme that is currently active. An active scheme is the one that is
	 * currently dictating which bindings will actually work. This value may be
	 * <code>null</code> if there is no active scheme. If the active scheme
	 * becomes undefined, then this should automatically revert to
	 * <code>null</code>.
	 */
	private Scheme activeScheme = null;
	/**
	 * The array of scheme identifiers, starting with the active scheme and
	 * moving up through its parents. This value may be <code>null</code> if
	 * there is no active scheme.
	 */
	private String[] activeSchemeIds = null;
	/**
	 * The number of bindings in the <code>bindings</code> array.
	 */
	private int bindingCount = 0;
	/**
	 * A cache of context IDs that weren't defined.
	 */
	private Set bindingErrors = new HashSet();
	/**
	 * The array of all bindings currently handled by this manager. This array
	 * is the raw list of bindings, as provided to this manager. This value may
	 * be <code>null</code> if there are no bindings. The size of this array
	 * is not necessarily the number of bindings.
	 */
	private Binding[] bindings = null;
	/**
	 * A cache of the bindings previously computed by this manager. This value