Add Abugidas and CJK/Emoji variation selectors.

Indian Abugidas such as Tamil are a pain to get rendering correctly. Indian Abugidas kinda always get the short end of the stick when it comes to unicode encodings.

CJK variation selectors should force CJK Unified ideographs to render according to a certain language. See https://heistak.github.io/your-code-displays-japanese-wrong/. And they should also affect Emoji.