Bug 206489 [Markers] Tasks column too small in the new markers view
Tasks column too small in the new markers view. We need to take into account the twistie.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/provisional/views/markers/ExtendedMarkersView.java
IContext context = ((IContextProvider) provider)
						.getContext(viewer.getControl());
				PlatformUI.getWorkbench().getHelpSystem().displayHelp(context);
			}
		});
		registerContextMenu();
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.ui.part.WorkbenchPart#dispose()
	 */
	public void dispose() {
		super.dispose();
		updateJob.cancel();
		instanceCount--;
		if (clipboard != null)
			clipboard.dispose();
		IDEWorkbenchPlugin.getDefault().getPreferenceStore()
				.removePropertyChangeListener(preferenceListener);
	}
	/**
	 * Get all of the filters for the receiver.
	 * 
	 * @return Collection of {@link MarkerFieldFilterGroup}
	 */
	public Collection getAllFilters() {
		return builder.getGenerator().getAllFilters();
	}
	/**