Decode the input before building XML commands.

[xunam]

As spotted in issue #53, Coquille chokes on non-ASCII input because of encoding problems and Python throwing UnicodeDecodeError exceptions. This is a simple fix for the issue, it consists in

• decoding the text from Vim's buffer when creating an XML command (the data we get from Vim is a byte string as a Python str, we turn it into a unicode following the buffer's encoding)
• accepting the unicode type in command encoding.

My first tests work fine but it surely deserves to be checked.

[dadoomer]

Indeed, this seems to solve the problem for me.

[dustnnbones]

@xunam do you have an example of how you fixed the issue?

[xunam]

Hi, I'm not sure what you mean by "example" here, but if I remember well, I fixed the issue by patching the code as in the present PR, which has no conflict according to Github. But it seems that this repository has been unmaintained for 6 years now.

Actually, I ended up writing my own Coq plugin from scratch to support later versions of Coq instead of forking coquille, because the way Coq interacts has changed completely : https://framagit.org/manu/coq-au-vim
It has a few open issues but it works reasonably well for me. Feel free to try it !