Sometimes the GC just won't run the finalizers, so we output a warning
instead of throwing an error, so now the test-suite will pass but with a
warning if the number of objects is not as expected.
Was notably failing on RHEL6 using OpenSUSE build testing with openjdk-1.6
These typemaps are currently defined for C#, Java and Python only and the
tests are provided only for these languages.
Also add a brief description of the new header to the documentation.
