Encoding fixes for python 3.4

In **python 3.x** `PyUnicode_FromString()` function accepts an **UTF-8** encoded strings only.
But `country_code`, `country_name`, `country_continent` are all **ISO-8859-1** encoded.
This commit fixes the issue.

Before fix:
```python
Python 3.4.1 (default, Aug 21 2014, 16:21:32) 
[GCC 4.6.3] on linux
>>> import GeoIP
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xe7 in position 4: invalid continuation byte
```

After fix:
```python
Python 3.4.1 (default, Aug 21 2014, 16:20:07) 
[GCC 4.6.3] on linux
>>> import GeoIP
>>> GeoIP.country_names['CW']
'Curaçao' 
```