Add director.swg for Go as was completely absent.
This is just the start of a common exception handling approach to directors.
An exception thrown in a Java director method will be propogated back to
Java via a C++ DirectorException.
DirectorException throws typemap for Java is fully working, all other languages need work.
DirectorException throws typemap for Perl added just to fix compilation errors.
Add director_exception_catches test.
