- abandon @NullableByDefault,
- add a boolean parameter to @NonNullByDefault for canceling defaults
  - implementation uses new TagBits.AnnotationNullUnspecifiedByDefault to represent @NonNullByDefault(false), 
  - similarly, Constants NULL_UNSPECIFIED represents explicit absence of a null annotation
- new warning for redundant @NonNull within a scope with default
- new error if annotation name is not a FQN
- abandon warning token "nullcontract", subsume under "null"

diff --git a/contrib/org.eclipse.objectteams.jdt.nullity/src/org/eclipse/objectteams/internal/jdt/nullity/problem_messages.properties b/contrib/org.eclipse.objectteams.jdt.nullity/src/org/eclipse/objectteams/internal/jdt/nullity/problem_messages.properties
index a4b0918..cf39dd9 100644
--- a/contrib/org.eclipse.objectteams.jdt.nullity/src/org/eclipse/objectteams/internal/jdt/nullity/problem_messages.properties
+++ b/contrib/org.eclipse.objectteams.jdt.nullity/src/org/eclipse/objectteams/internal/jdt/nullity/problem_messages.properties
@@ -22,4 +22,6 @@
 918 = Missing null annotation: inherited method from {1} declares this parameter as @{2}
 919 = Potential null pointer access: The method {0} may return null
 920 = Redundant null check: The method {0} cannot return null
-921 = The method {0} from class {1} cannot implement the corresponding method from type {2} due to incompatible nullness constraints. 
\ No newline at end of file
+921 = The method {0} from class {1} cannot implement the corresponding method from type {2} due to incompatible nullness constraints
+922 = Cannot use the unqualified name ''{0}'' as an annotation name for null specification
+923 = The nullness annotation is redundant with a default that applies to this location
\ No newline at end of file