: upgrade to CLDR 28 and necessary adjustments

cldr:
- needed to excluded "validity" directory as it contains xml data
  not specific to locales.

language and internal:
- CompactIndex now supports *all* locales for which there are data
  files and not just the ones which have data. This is necessary to
  not drop en-US. Seems better anyway. This increases table size, but
  added comment about a trick that could be used to reduce it again in
  the future.
- Skipping more match data entries. My suspicion is that this is
  supported anyway, but needs to be verified (TODO added).

language/display:
- manually removed support for "private use" script names are their
  coverage is spotty and questionable.
- manually override coverage test for az_Arab: not supported by
  English, but seems to have good data for languages for which this
  may be relevant.

currency:
- minor changes in test code and generation code to adapt to
  change data.
- manually added MVP as currency as it doesn't appear to be added
  otherwise.

Note that search and collate are still stuck on old revisions.

Change-Id: I2b2b2cba66caaff7c027fcb421f99595430e31dd
Reviewed-on: https://go-review.googlesource.com/17802
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
15 files changed