Add history and editing feature to line input mode

Use up and down arrow keys to navigate history.

Use left and right arrow keys to move cursor back and forth.

We try mimic the behaviour of GNU readline which we can not use because
we also need to react to key commands.

src/print.h

@@ -134,6 +134,7 @@ extern char ansi_format[];
 #define tio_debug_printf_raw(format, args...)
 #endif
 
+void print(const char *format, ...);
 void print_hex(char c);
 void print_normal(char c);
 void print_init_ansi_formatting(void);