Ascii values of hex characters

With some version of Python the following checks return always False, resulting in few addresses being decoded:

(in output.py)

```
if len(hex_data) == 65 and hex_data[0] == 4:
if len(hex_data) == 33 and hex_data[0] in [2, 3]:
```

I would suggest doing this:

```
if len(hex_data) == 65 and ord(hex_data[0]) == 4:
if len(hex_data) == 33 and ord(hex_data[0]) in [2, 3]:
```

