Add the generation of C++ classes.

	Add the generation of C++ classes.
	* spu.c (version_string): Bump to 0.5.
	(DEFAULT_NUM_CLASSES, DEFAULT_NUM_LIB_CLASSES,
	DEFAULT_NUM_METHODS): New macros.
	(enum decl_types): Add d_class.
	(struct class_desc): New struct.
	(struct function_desc): Add class field.
	(num_classes, num_lib_classes, num_methods, classes, lib_classes):
	New globals.
	(main): Add --classes and --methods options.
	(display_usage): Mention them.
	(add_decl_to_table): Add d_class and default cases.
	(create_classes, create_class, write_class): New functions.
	(write_header_file, write_lib_header_file): Write classes.
	(write_function): Format class methods differently.

	(lang_names): New global.
	(main): Use c++ instead of cpp in --language.
	(write_description_block): Write out all parameter settings.
	* README: Update version number.