Do not allow substituting alternates or drafts in derived locales (#1113)

Do not allow substituting alternates or drafts in derived locales (#1113)

* download_import_cldr.py: pass remaining arguments through to import_cldr

* Do not allow substituting alternates or drafts in derived locales

For more coverage, we've allowed using alternate or draft values
when no officially accepted values have been present.

However, non-global (i.e. e.g. `de_CH` locales) may have an alternate
spelling for what would be an alternate in the parent locale (and
that alternate hasn't been imported into the parent), and the import
would have then accepted the alternate from the child locale as a
non-alternate.

Refs #1112