R6 package for the annotations. The code uses
strings (and had 3 error before I got the string right, long
live Java). So the package is only in the test code
#477 The method's return type was interpreted as raw type
bnd diffing only looked at the raw type of a return. It now uses
the generic signature of the return type. This will now
give a diff on a change from Collection<String> to 
Collection<Integer>. Since it uses the string representation
of the signature, Due to lack of time, I use the binary
form of the signature. So messages might look awkward. On the 
TODO list ...
Extra tests