use rustyline to replace readline

Cargo.toml

@@ -30,6 +30,7 @@ pam-sys = "0.5"
 pin-utils = "0.1.0-alpha"
 proxmox = { git = "ssh://gitolite3@proxdev.maurer-it.com/rust/proxmox", version = "0.1", features = [ "sortable-macro", "api-macro" ] }
 regex = "1.0"
+rustyline = "5.0.4"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
 shellwords = "1.0"