Shell: Implement redirections

This works well enough. At the moment redirections can appear anywhere
in the command **after** environment variables and possible alias
command. This means commands like `>foo echo hello` are not supported.
I don't think this is big enough problem for now (99% time redirections
are given after arguments) that i would rewrite the environment and
alias parsing.

userspace/programs/Shell/Token.cpp

@@ -27,6 +27,12 @@ void Token::debug_dump() const
 		case Type::DoubleQuote:
 			dprintln("Token <DoubleQuote>");
 			break;
+		case Type::GreaterThan:
+			dprintln("Token <GreaterThan>");
+			break;
+		case Type::LessThan:
+			dprintln("Token <LessThan>");
+			break;
 		case Type::OpenCurly:
 			dprintln("Token <OpenCurly>");
 			break;