Support python3

[ppershing]

Python 3.5 is not very happy:

  Running setup.py install for bottle-auth
      File "/var/www/venv/lib/python3.5/site-packages/bottle_auth/social/facebook.py", line 34
        except HTTPRedirect, e:
                           ^
    SyntaxError: invalid syntax

      File "/var/www/venv/lib/python3.5/site-packages/bottle_auth/social/twitter.py", line 29
        except HTTPRedirect, e:
                           ^
    SyntaxError: invalid syntax

      File "/var/www/venv/lib/python3.5/site-packages/bottle_auth/social/google.py", line 31
        except HTTPRedirect, e:
                           ^
    SyntaxError: invalid syntax

      File "/var/www/venv/lib/python3.5/site-packages/bottle_auth/core/escape.py", line 223
        _URL_RE = re.compile(ur"""\b((?:([\w-]+):(/{1,3})|www[.])(?:(?:(?:[^\s&()]|&amp;|&quot;)*(?:[^!"#$%&'()*+,.:;<=>?@\[\]^`{|}~\s]))|(?:\((?:[^\s&()]|&amp;|&quot;)*\)))+)""")
                                                                                                                                                                                 ^
    SyntaxError: invalid syntax

      File "/var/www/venv/lib/python3.5/site-packages/bottle_auth/core/httpclient.py", line 101
        except (httplib.error, socket.error, IOError), e:
                                                     ^
    SyntaxError: invalid syntax

I'm available to make this support Python 3.x.