Address issues raised by W.S. Fulton - naming conventions, introduced dependencies.

Change methods to functions in swig namespace, and emit separately
from director class.  Moved added utility functions to separate ".swg"
file, java/director_except_utils.swg. Allow generation of these
utility functions to be completely disabled (to allow removal of
std::string dependency) using noutils attribute on director:except
feature. Rename GetMessage to Swig::get_exception_message, and
ExceptionMatches to Swig::exception_matches.