GRAILS-10024 added new ParticipatingInterceptor interface that allows us to reset the participate flag to ensure the session is closed at the end of the request
update version to 2.1.5
GRAILS-10024 also need AggregatePersistenceContextInterceptor to implement ParticipatingInterceptor
GRAILS-9644 - list() with args only returns one projection property
GRAILS-10047 - fix binding to a class with no bindable properties
Merge branch '2.1.x' into 2.2.x

Conflicts:
	build.gradle
	build.properties
	grails-test-suite-uber/src/test/groovy/grails/util/GrailsUtilTests.java
	grails-web/src/main/groovy/org/codehaus/groovy/grails/web/binding/DefaultASTDatabindingHelper.java
	grails-web/src/test/groovy/org/codehaus/groovy/grails/web/binding/DefaultASTDatabindingHelperSpec.groovy