Python 3.x support?#26

It does not appear python-whois has Python 3.x support. As 3.x grows more commonplace, this will become a serious obstacle to adoption. Some problems I ran into: ``` ~/python-whois$ python3 pwhois File "pwhois", line 6 except ImportError, e: ^ SyntaxError: invalid syntax ~/python-whois$ python3 Python 3.4.0 (default, Apr 11 2014, 13:05:11) [GCC 4.8.2] on linux Type "help", "copyright", "credits" or "license" for more information. >>> from pythonwhois import get_whois >>> get_whois('google.com') Traceback (most recent call last): File "<stdin>", line 1, in <module> File "/home/fsufitch/python-whois/pythonwhois/__init__.py", line 4, in get_whois raw_data = net.get_whois_raw(domain) File "/home/fsufitch/python-whois/pythonwhois/net.py", line 15, in get_whois_raw domain = encode( domain if type(domain) is unicode else decode(domain, "utf8"), "idna" ) NameError: name 'unicode' is not defined ``` There may be other problems too, but I do not have the time to conduct a code review of it right now. Thanks for looking into this! I really wanted to use `pythonwhois` but my project is unfortunately python3-only.