GRAILS-11357 remove GrailsPageFilter (SiteMeshFilter)
handle adding url mappings filter when no previous filter exists
return null if inner view returns null
GRAILS-11357 Spring configurer (bean factory post processor) for GrailsLayoutViewResolver
update concurrentlinkedhashmap-lru to 1.4 version
make GrailsPageResponseWrapper.getContentType return only the contentType that has been set to the wrapper instance