Bug 21013 [PropertiesView] ComboBoxPropertyDescriptor should provide a defualt label provider
ComboBoxPropertyDescriptor requires an array of string values in its contructor. These are used to display in the combo box cell editor. Typically clients must also supply a label provider with the same array of values in order to show the correct value when the cell editor is not active. The descriptor should create a default label provider based on the values passed in its constructor.
bundles/org.eclipse.ui.views/src/org/eclipse/ui/views/properties/PropertyDescriptor.java
* This prevents a property from displaying during multiple 
 * selection.
 *
 * @return <code>true</code> to indicate always incompatible
 */
protected boolean getAlwaysIncompatible() {
	return incompatible;
}
/**
 * The <code>PropertyDescriptor</code> implementation of this 
 * <code>IPropertyDescriptor</code> method returns the value set by
 * the <code>setCategory</code> method. If unset, this method returns
 * <code>null</code> indicating the default category.
 *
 * @see #setCategory
 */
public String getCategory() {
	return category;
}
/**
 * The <code>PropertyDescriptor</code> implementation of this 
 * <code>IPropertyDescriptor</code> method returns the value set by
 * the <code>setDescription</code> method. If unset, this method returns
 * <code>null</code> indicating no description.
 *
 * @see #setDescription
 */
public String getDescription() {
	return description;
}