Determine columns needed for a fixed-size wide-character string
wcwidth is a simple JavaScript port of wcwidth implemented in C by Markus Kuhn.
JavaScript port originally written by Woong Jun woong.jun@gmail.com (http://code.woong.org/)
'한'.length // => 1
wcwidth('한'); // => 2
'한글'.length // => 2
wcwidth('한글'); // => 4
wcwidth() and its string version, wcswidth() are defined by IEEE Std
1002.1-2001, a.k.a. POSIX.1-2001, and return the number of columns used
to represent the given wide character and string.
Markus's implementation assumes the wide character given to those
functions to be encoded in ISO 10646, which is almost true for
JavaScript's characters.
MIT