I opened citeproc.xsl in oXygen, and the encoding for the file was
definitely not utf-8. I fixed it, and committed it.
Please make sure you've got your editor configured properly so we don't
end up with a bunch of files like this.
Also, one thing to note that I recently learned is that you can commit a
group of files. So say you make changes to three files, which are all
part of the same fix, you can just do, from the citeproc/ directory