[AESH-59]
added Key to abstract away the use of int[] for KeyOperations.
may need to add a custom Key for "unknown" key combinations
[AESH-65]
moved masking into Prompt
[AESH-67]
created ConsoleCallback
[AESH-67]
added return value
[AESH-68]
Console will now spawn a new thread to read from the terminal
ConsoleCallback must be set to start.