Bug 65187 [Themes] Cascading*Registry leakage from Colors and Fonts pref page
Small leak on I20040529 For each ColorsAndFontsPreferencePage this is created, the cascading font and color registries are leaked. This is because the superclasses register a runnable with Display#disposeExec
bundles/org.eclipse.jface/src/org/eclipse/jface/resource/FontRegistry.java
return StringConverter.asFontData(value.trim());
        } catch (DataFormatException e) {
            throw new MissingResourceException(
                    "Wrong font data format. Value is: \"" + value + "\"", getClass().getName(), value); 
        }
    }
    /**
     * Adds (or replaces) a font to this font registry under the given
     * symbolic name.
     * <p>
     * A property change event is reported whenever the mapping from
     * a symbolic name to a font changes. The source of the event is
     * this registry; the property name is the symbolic font name.
     * </p>
     *
     * @param symbolicName the symbolic font name
     * @param fontData an Array of FontData
     */
    public void put(String symbolicName, FontData[] fontData) {
        put(symbolicName, fontData, true);
    }
    /**
     * Adds (or replaces) a font to this font registry under the given
     * symbolic name.
     * <p>
     * A property change event is reported whenever the mapping from
     * a symbolic name to a font changes. The source of the event is
     * this registry; the property name is the symbolic font name.
     * </p>
     *