Unify actions and commands

	Unify actions and commands

	* defs.h (read_command_lines, read_command_lines_1): New
	parameters validator and closure.
	* tracepoint.h (struct action_line): Remove.
	* breakpoint.h (struct breakpoint): Remove the 'actions'
	field.
	* defs.h (enum command_control_type): New value
	while_stepping_control.
	(struct command_line): Add comments.
	* breakpoint.c (breakoint_is_tracepoint): New.
	(breakpoint_set_commands): For tracepoints,
	verify the commands are permissible.
	(check_tracepoint_commands): New.
	(commands_command): Require that each new line is validated using
	check_tracepoint_command, if we set commands for a tracepoint.
	(create_tracepoint_from_upload): Likewise.
	(print_one_breakpoint_location): Remove the code to print
	actions specifically.
	(tracepoint_save_command): Relay to print_command_lines.
	* cli/cli-script.c (process_next_line): New parameters validator
	and closure. Handle 'while-stepping'. Call validator if not null.
	(read_command_lines, read_command_lines1): Likewise.
	(recurse_read_control_structure): New parameters validator and
	closure. Handle while_stepping_control.
	(print_command_lines): Handle while-stepping.
	(get_command_line, define_command, document_command): Adjust.
	* remote.c (remote_download_tracepoint): Adjust.
	* tracepoint.c (make_cleanup_free_actions, read_actions)
	(free_actions, do_free_actions_cleanup): Remove.
	(trace_actions_command): Use read_command_lines.
	(validate_actionline): Use error in one place.
	(encode_actions_1): New, extracted from...
	(encode_actions): ...this. Also use cleanups for exception
	safety.
	(trace_dump_command): Adjust.
	* mi/mi-cmd-break (mi_cmd_break_commands): Validate commands if
	it's tracepoint.