Split director_exception testcase into two so that testing throw(),
with no arguments, that is nothrows, can be tested separately to throw()
taking arguments. [The throw keyword needs to be removed for C++
compilation in C++11 and later when it was deprecated.]
director method - PHP NULL gets returned by the subclassed method
in this case, so the directorout typemap needs to allow that (at
least if an exception is active).
