Bug 82260 ResultCollector: remove dependency to internal J Core interface
I20050104-1600 Summary says it all.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/JavaPlugin.java
* Backwards compatibility: set the Java editor tab width in this plug-in's
		 * preference store with the old key to let older versions access it.
		 * Since 3.0 the tab width is managed by the extended texteditor and
		 * uses a new key.
		 */
		getPreferenceStore().putValue(oldTabWidthKey, getPreferenceStore().getString(newTabWidthKey));
		fPropertyChangeListener= new IPropertyChangeListener() {
			public void propertyChange(PropertyChangeEvent event) {
				if (newTabWidthKey.equals(event.getProperty()))
					getPreferenceStore().putValue(oldTabWidthKey, getPreferenceStore().getString(newTabWidthKey));
			}
		};
		getPreferenceStore().addPropertyChangeListener(fPropertyChangeListener);
		
		/*
		 * Backward compatibility for the refactoring preference key. 
		 */
		getPreferenceStore().setValue(
			PreferenceConstants.REFACTOR_ERROR_PAGE_SEVERITY_THRESHOLD, 
			RefactoringCore.getConditionCheckingFailedSeverity());
	}
	
	/**
	 * Uninstalls backwards compatibility for the preference store.
	 */
	private void uninstallPreferenceStoreBackwardsCompatibility() {
		JFaceResources.getFontRegistry().removeListener(fFontPropertyChangeListener);
		getPreferenceStore().removePropertyChangeListener(fPropertyChangeListener);
	}