As I've said before, my changes to the "help" command has broken help.exp 
tests and some others. This patch fixes help.exp failrues. It also introduces
some new functions to help make the tests readable and remove duplication.
The taken approach is the one outlined in:

	http://sources.redhat.com/ml/gdb/2006-11/msg00001.html

namely that we should not bother to test the explicit list of subcommands, 
because that does not help anything.

OK?

- Volodya

	* gdb.base/help.exp (help_test_raw): New.
	(test_class_help): New.
	(test_prefix_command_help): New.
	Adjust testcases.