incorrect requirements assumed for cmap (W0302)

The font validator generates warning W0302 when a font does not contain any cmap table for legacy 8-bit only Macintosh encodings.
Such warning should not be emitted if the font effectively does not cover at all any script for which there exists a legacy 8-bit Macintosh encoding. For example in most Asian scripts.

The font validator help also states incorrectly:
"For Microsoft fonts, at least two subtables are required within the cmap table: Format 4 (Windows) and Format 0 (Macintosh) subtables."

This should not say "are required", for the same reason. There's absolutely no interest in adding a Macintosh cmap where almost all mappings (except a few like NULL, CR, RS, SPACE or NBSP) will be to ".notdef". This requirement should only be true for Latin fonts.

Same remark about warnings associated with incorrect "requirements" for Windows in the help file:
- W0305 (missing mapping for the Euro symbol U+20AC, also superfluous if this is not a font with coverage of Latin, Greek and/or Cyrillic).
- W0304 (missing mapping for the Euro symbol in the Macintosh cmap at position 219, only needed if there's such a cmap)
- W0301 (missing mapping for the Apple logo, superfluous if there's no Macintosh cmap, because it's not needed),
- W0300 (missing mapping for the Apple logo in the Macintosh cmap at position 240, only needed if there's such a cmap)