TODO-Scripts

* Add Tulu-Tigalari to the scx of of U+A8F1 after we encoded Tulu-Tigalari:
  http://www.unicode.org/L2/L2015/15162-devanagari-combining-avagraha-prop.pdf
* Go over L2/15-164 and see if there should be any additions to
  ScriptExtensions.
* Find out if Arabic percent sign, decimal separator, and percent sign are
  used in Thaana (either historically or presently).
* Add Tulu-Tigalari to scx of Indic fractions:
  http://www.unicode.org/L2/L2015/15243-kannada-frac.pdf