* Add characters:
  - COMBINING TRIPLE DOT (`U+1AB4`).
  - COMBINING TRIPLE ACUTE ACCENT (`U+1ACB`).
  - GIMEL SYMBOL (`U+2137`) (#1708).
  - DALET SYMBOL (`U+2138`) (#1708).
  - ROTATED CAPITAL Q (`U+213A`) (#1704).
  - LATIN EPIGRAPHIC LETTER SIDEWAYS I (`U+A7F7`) (#1704).
  - CYRILLIC CAPITAL LETTER ZEMLYA (`U+A640`) ... CYRILLIC SMALL LETTER DZELO (`U+A643`).
  - CYRILLIC CAPITAL LETTER NEUTRAL YER (`U+A64E`).
  - CYRILLIC SMALL LETTER NEUTRAL YER (`U+A64F`).
  - CYRILLIC CAPITAL LETTER REVERSED TSE (`U+A660`) ... CYRILLIC LETTER MULTIOCULAR O (`U+A66E`).
  - CYRILLIC CAPITAL LETTER CROSSED O (`U+A69A`).
  - CYRILLIC SMALL LETTER CROSSED O (`U+A69B`).
  - LATIN SMALL LETTER BARRED E (`U+AB33`).
  - MONOGRAM FOR EARTH (`U+1D300`) ... TETRAGRAM FOR FOSTERING (`U+1D365`).
  - LATIN SMALL LETTER T WITH HOOK AND RETROFLEX HOOK (`U+1DF09`).
  - LATIN SMALL LETTER ESH WITH DOUBLE BAR (`U+1DF0B`).
  - LATIN SMALL LETTER ESH WITH DOUBLE BAR AND CURL (`U+1DF0C`).
* Fix glyph of MODIFIER LETTER RAISED INVERTED EXCLAMATION MARK (`U+A71E`) and MODIFIER LETTER LOW INVERTED EXCLAMATION MARK (`U+A71F`).
* Improve glyphs of MODIFIER LETTER GLOTTAL STOP (`U+02C0`) and MODIFIER LETTER REVERSED GLOTTAL STOP (`U+02C1`) for better disambiguation against MODIFIER LETTER SMALL REVERSED GLOTTAL STOP (`U+02E4`).
* Fix glyphs of AUSTRAL SIGN (`U+20B3`) and SOM SIGN (`U+20C0`).
* Fix glyph of COMBINING ASTERISK ABOVE (`U+20F0`).
* Fix glyphs of RING EQUAL TO (`U+2257`) and EQUALS WITH ASTERISK (`U+2A6E`).
* Fix glyph of IDENTICAL WITH DOT ABOVE (`U+2A67`).
* Fix variant application of `cv87` to `U+0298`.
* Disunify glyphs of LATIN LETTER SMALL CAPITAL BARRED B (`U+1D03`) and MODIFIER LETTER CAPITAL BARRED B (`U+1D2F`) from LATIN CAPITAL LETTER B WITH STROKE (`U+0243`).
* Fix variant assignments of italic long S under SS17 and SS18.
* Fix variant assignments of italic eszet under SS12, SS17, and SS18.
* Fix broken shape of double-struck `d` (#1716), `ff` ligature (#1717).
* Fix random broken placement of Decimal Exponent (#1718).
