[gexiv2] Python 2/3 and unicode

[Jim Easterbrook <jim jim-easterbrook me uk>]

I'm using the Python Gexiv2 bindings to read metadata from some .jpg 
files. Some of the files have EXIF data in the Latin-1 character set 
(yes, I know the EXIF spec says ASCII only).
In Python 2 I can cope with these files as 'get_tag_string' returns a 
Python 2 string, which I can then convert to unicode with the latin-1 
codec. In Python 3 'get_tag_string' returns a unicode string (as all 
Python 3 strings are unicode) after converting with the utf-8 codec. 
This raises the UnicodeDecodeError exception when it encounters some 
latin-1 characters.
Is there any way to change the codec used by 'get_tag_string' or to 
change its return type from unicode to bytes?
--
Jim Easterbrook                 <http://www.jim-easterbrook.me.uk/>