Add independent input and output mode

Replaces -x, --hexadecimal option with --intput-mode and --output-mode
so it is possible to select hex or normal mode for both input and output
independently.

To obtain same behaviour as -x, --hexadecimal use the following
configuration:

input-mode = hex
output-mode = hex

src/print.h

@@ -116,3 +116,4 @@ void print_hex(char c);
 void print_normal(char c);
 void print_init_ansi_formatting(void);
 void tio_printf_array(const char *array);
+void print_tainted_set(void);