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.h

@@ -19,6 +19,8 @@ public:
 		CloseParen,
 		Dollar,
 		DoubleQuote,
+		GreaterThan,
+		LessThan,
 		OpenCurly,
 		OpenParen,
 		Pipe,