Bug 186025 [Viewers] Virtual Manager should be cleared when Viewer is disposed
Got a nasty memory leak where the Workbench would keep my disposed viewer in a field since it was registered as a selection provider. In StructuredViewer#handleDisposed(), the input is set to null, however this does not clear a possible virtual manager being used from the Table Viewer. The Table Viewer should clear the cache of the virtual manager on handleDispose to make sure, no reference to any model object is retained.
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTableViewer.java
* @since 3.3
	 */
	protected abstract Item doGetItem(int index);
	/**
	 * Returns an array of {@link Item} that are currently selected in the
	 * receiver. The order of the items is unspecified. An empty array indicates
	 * that no items are selected.
	 *
	 * @return an array representing the selection
	 *
	 * @since 3.3
	 */
	protected abstract Item[] doGetSelection();
	/**
	 * Returns the zero-relative indices of the items which are currently
	 * selected in the receiver. The order of the indices is unspecified. The
	 * array is empty if no items are selected.
	 *
	 * @return an array representing the selection
	 *
	 * @since 3.3
	 */
	protected abstract int[] doGetSelectionIndices();
	/**
	 * Clears all the items in the receiver. The text, icon and other attributes
	 * of the items are set to their default values. If the table was created
	 * with the <code>SWT.VIRTUAL</code> style, these attributes are requested
	 * again as needed.
	 *
	 * @since 3.3