Contains classes defining the application context subinterface
for UI applications. The theme feature is added here.
  - If no UiApplicationContextUtils.THEME_SOURCE_BEAN_NAMEbean is available in the context or parent context, a defaultResourceBundleThemeSourcewill be created for requested themes. In this case, the base name of the property file will match
with the theme name.
- If the bean is available in the context or parent context, a basenamePrefixcan be
  set before the theme name for locating the property files like this:
 
  	<bean id="themeSource" class="org.springframework.ui.context.support.ResourceBundleThemeSource">
	
 <property name="basenamePrefix"><value>theme.</value></property>
 </bean>
 in this case, the themes resource bundles will be namedtheme.<theme_name>XXX.properties.
  
- This can be defined at application level and/or at servlet level for web applications.
- Normal i18n features of Resource Bundles are available. So a theme message can be dependant
  of both theme and locale.
- If messages in the resource bundles are in fact paths to resources(css, images, ...), make sure these resources
  are directly available for the user and not, for example, under the WEB-INF directory.
Web packages add the resolution and the setting of the user current theme.