8029230: Update copyright year to match last edit in jdk8 langtools repository for 2013
Reviewed-by: ksrini
Contributed-by: steve.sides@oracle.com

6537020: JCK tests: a compile-time error should be given in case of ambiguously imported fields (types, methods)
Summary: Hiding check does not support interface multiple inheritance
Reviewed-by: jjg

6968063: provide examples of code that generate diagnostics
Reviewed-by: mcimadamore