Bug 93245 [Dialogs] Error messages show up in two locations in the properties dialog
Force an error message: 1) select a Java project 2) open the properties dialog 3) navigate to Java Compiler>Building 4) enable project specific settings 5) enter a letter into the maximum number of problems field ->the error message shows up at the bottom 6) resize the dialog ->the error message also shows up in the banner
bundles/org.eclipse.jface/src/org/eclipse/jface/preference/PreferencePage.java
*/
    public IPreferencePageContainer getContainer() {
        return container;
    }
    /**
     * Returns the preference store of this preference page.
     *
     * @return the preference store , or <code>null</code> if none
     */
    public IPreferenceStore getPreferenceStore() {
        if (preferenceStore == null)
            preferenceStore = doGetPreferenceStore();
        if (preferenceStore != null)
            return preferenceStore;
        else if (container != null)
            return container.getPreferenceStore();
        return null;
    }
    /**	
     * The preference page implementation of an <code>IPreferencePage</code>
     * method returns whether this preference page is valid. Preference
     * pages are considered valid by default; call <code>setValid(false)</code>
     * to make a page invalid.
     */
    public boolean isValid() {
        return isValid;
    }
    /**
     * Suppresses creation of the standard Default and Apply buttons
     * for this page.