Support Unicode 9 prepended concatenation marks

[mathiasbynens]

It’s still a proposal for now, but hey. http://blog.unicode.org/2015/11/new-character-property-for-prepended.html Prepended_Concatenation_Mark

[Mottie]

Just curious... it looks like Prepended_Concatenation_Marks were added in Unicode 8 (ref)? I do see mention of these marks in Unicode 9, but I can't tell if any new ones were added.

And on that note... the package.json for this library is still using Unicode 8, shouldn't it be updated for v9?

[mathiasbynens]

http://unicode.org/reports/tr29/#Table_Combining_Char_Sequences_and_Grapheme_Clusters