GRAILS-8805 make it possible to create non-cached Template from String instance
GRAILS-8805 related: implement clearCache for view resolver
Merge branch '2.3.x' into 2.4.x

Conflicts:
	grails-web-gsp/src/main/groovy/org/codehaus/groovy/grails/web/servlet/view/GroovyPageViewResolver.java
GRAILS-11525 fix scaffolded view template reloading when domain class changes
- don't cache scaffolded views in GroovyPagesTemplateEngine