Delete legacy code no longer used in project * configure.ac: Drop checks for headers and functions no longer needed. * exceptions.cc, exceptions.h: Delete pytave::init_exceptions and related methods and properties for registering exceptions with Boost.Python runtime. * octave_to_python.cc, octave_to_python.h (pytave::octlist_to_pytuple): Delete. * python_to_octave.cc, python_to_octave.h (pytave::pytuple_to_octlist): Delete.