encoding of torrent

[bearsprite@gmail.com]

1. In deluge/ui/common.py, use some code to guess a encoding, and use the encoding to convert the mbcs string to utf8 string

self.__m_name = decode_string(self.__m_metadata["info"]["name"], self.encoding)

but why not:

self.__m_name = self.__m_metadata["info"]["name.utf-8"]

field "XXXX" is a mbcs, but field "XXXX.utf-8" is just a utf8!

2. for f in self.__m_metadata["info"]["files"]:
       self.__m_files.append({
           'path': decode_string(os.path.join(prefix, *f["path"])),
           'size': f["length"],
           'download': True
       })
   

here "prefix" is already a utf8, but f[ "path" ] is a mbcs yet, so os.path.join is invalid

[andar]

1. Not all torrents have this key, but I have added support to use it if available.

2. I have changed it to decode/encode the path before joining it with the prefix.

In [5265].

Thanks!