GROOVY-6640: Compilation warning when using @AutoClone on an object with collection properties
refactor some utility methods to a more logical place
Merge branch 'master' into traits-implementation

Conflicts:
	src/main/org/codehaus/groovy/transform/AbstractASTTransformation.java
	src/main/org/codehaus/groovy/transform/DelegateASTTransformation.java