GRAILS-9739 flush the session at the end of withNewSession unless it's been set to manual
GRAILS-9106 changed from implementing HttpServletRequest and HttpServletResponse to using a JDK proxy to avoid Servlet API version issues
update instructions for building Grails
Merge branch '2.0.x' into 2.1.x
Merge branch '2.1.x' into 2.2.x

Conflicts:
	grails-hibernate/src/main/groovy/org/codehaus/groovy/grails/orm/hibernate/HibernateGormEnhancer.groovy
	grails-web/src/main/groovy/grails/gsp/PageRenderer.groovy