Changes of version 31.1.0

• Add characters:
  • BLACK-LETTER CAPITAL H (U+210C) (#714).
  • BLACK-LETTER CAPITAL I (U+2111) (#714).
  • BLACK-LETTER CAPITAL R (U+211C) (#714).
  • BLACK-LETTER CAPITAL Z (U+2128) (#714).
  • BLACK-LETTER CAPITAL C (U+212D) (#714).
  • LATIN SMALL LETTER BLACKLETTER E (U+AB32) (#2443).
  • LATIN SMALL LETTER BLACKLETTER O (U+AB3D) (#2443).
  • LATIN SMALL LETTER BLACKLETTER O WITH STROKE (U+AB3E) (#2443).
  • LEFT-POINTING ROCKET SHIP (U+1CC56) ... DOWN-POINTING ROCKET SHIP (U+1CC59) (Proposed for Unicode 16; L2/21-235).
  • LEFT-POINTING ATOMIC BOMB (U+1CC60) ... DOWN-POINTING ATOMIC BOMB (U+1CC63) (Proposed for Unicode 16; L2/21-235).
  • LEFT-POINTING RIFLE (U+1CC65) ... DOWN-POINTING RIFLE (U+1CC68) (Proposed for Unicode 16; L2/21-235).
  • MOON LANDER (U+1CDF5) (Proposed for Unicode 16; L2/21-235).
  • UP-POINTING FROG (U+1CDFB) (Proposed for Unicode 16; L2/21-235).
  • DOWN-POINTING FROG (U+1CDFC) (Proposed for Unicode 16; L2/21-235).
  • MATHEMATICAL FRAKTUR CAPITAL A (U+1D504) .. MATHEMATICAL FRAKTUR SMALL Z (U+1D537) (#444).
  • MATHEMATICAL BOLD FRAKTUR CAPITAL A (U+1D56C) .. MATHEMATICAL BOLD FRAKTUR SMALL Z (U+1D59F) (#444).
• Add separate variant selectors for Cyrillic Capital En/Er (VXAA, VXAB).
• Add variant selectors for Greek lower Beta/Gamma/Nu/Upsilon (VXAC, VXAD, VXAE, VXAF).
• Optimize glyph for VERTICAL LINE WITH MIDDLE DOT (U+2327).
• Improve k (cv46) and x (cv58) variants used by ss03, ss08, ss09, ss10, ss12, ss14, and ss18 under slab italic.