update wcwidth data from utf8proc
Character width data being out of date is a constant source
of weird rendering issues and wasted time trying to diagnose
those, e.g. as reported by Jeremy Chadwick:
Sadly, there is no real ("standard") wcwidth data source, so
this tries to rectify the problem using the utf8proc one (through
its C API) which would hopefully benefeat both FreeBSD and
utf8proc through bug reports (if any).