metadata/AnnotationInstantiation: Change the @Target elements of @AnnotationInstantiation so we can annotation default parameter methods with @AnnotationInstantiation if they invoke annotation classes or constructors. See ceylon/ceylon-compiler#1221.
Add @AnnotationInstantiationTree so we can serialize nested invocations of annotation constructors and classes. See ceylon/ceylon-compiler#1221.
Rename @AnnotationInstantiation.annotationClass() -> primary() since it is now used for annotation _constructors_ in some circumstances. See ceylon/ceylon-compiler#1221.
Metamodel: Add a DeclarationParser so we can parse Strings stored in annotations into Declarations. See ceylon/ceylon-compiler#1140.