Create InputHandler which performs C0 actions

Part of #459

src/Interfaces.ts

@@ -32,3 +32,16 @@ export interface ITerminal {
   scrollDisp(disp: number, suppressScrollEvent: boolean);
   cancel(ev: Event, force?: boolean);
 }
+
+/**
+ * Handles actions generated by the parser.
+ */
+export interface IInputHandler {
+  bell(): void;
+  lineFeed(): void;
+  carriageReturn(): void;
+  backspace(): void;
+  tab(): void;
+  shiftOut(): void;
+  shiftIn(): void;
+}