Refactor and squash long-standing bugs (A2)

This is awesome.
- Improve performance by stopping useless string/array conversions.
- Simplify method interface.
- Fix localization bugs - we now know our locale
- Fix bugs with surrogate code points

Bug: 4769095
Change-Id: I8a8ee224b713429ee0a4ce5bd52f1b63378cf56f