language: update matching algorithm

Using the new data:
- region grouping data to ultimately replace
  region distance
- allow making regions more specific if it falls
  within an enclosing region
- added CLDR test file (work in progress)
- added same-script rule

Change-Id: Ib2f279aefec871d9a0c13c105749623a93bb911a
Reviewed-on: https://go-review.googlesource.com/47346
Run-TryBot: Marcel van Lohuizen <mpvl@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Nigel Tao <nigeltao@golang.org>
7 files changed