ADD some functions of Virtual Shell

	修改:         web/include/css/shell.css
	UPDATE .user_name => .command_title

	修改:         web/include/js/interface.js
	ADD a line of introduction to use $vs:help

	修改:         web/include/js/shell.js
	FIX $vs:clean => $vs:clear
	ADD AddAnyCommandBox function to define varies functions