Changes of version 26.2.0

• Add variant selectors for lowercase Greek Pi (π) and Tau (τ) (#1924).
• Add characters:
  • CYRILLIC SMALL LETTER ROUNDED VE (U+1C80).
  • CYRILLIC SMALL LETTER TALL TE (U+1C84) (#1911).
  • CYRILLIC SMALL LETTER TALL HARD SIGN (U+1C86) (#1911).
  • CYRILLIC SMALL LETTER TALL YAT (U+1C87) (#1911).
  • LEFTWARDS OPEN-HEADED ARROW (U+21FD) ... LEFT RIGHT OPEN-HEADED ARROW (U+21FF) (#1912).
  • DIAMETER SIGN (U+2300) (#1923).
  • CIRCLE WITH SUPERIMPOSED X (U+29BB).
  • LEFTWARDS TWO-HEADED ARROW WITH TRIANGLE ARROWHEADS (U+2BEC) ... DOWNWARDS TWO-HEADED ARROW WITH TRIANGLE ARROWHEADS (U+2BEF).
  • CLOCK FACE ONE OCLOCK (U+1F550) ... CLOCK FACE TWELVE-THIRTY (U+1F567) (#1850).
• Make below marks to avoid bottom-right Ogoneks (#1789).
• Use oval shape for Empty Set symbols to distinguish with O-Slash (#1822).
• Implement leaning mark mechanism for F, L, P, b, d, h, k, p, q, r to get better mark placement. Now, "narrow" marks will align to these letters' extension parts (#1851).
• Add variant selection for Guillemets (#1899).
• Fix detached cedilla in Hookless asymmetric LATIN SMALL LETTER T WITH CEDILLA (U+0163) (#1914).
• Fix broken hookless/tailless/asymmetric t variants in ſt ligature (U+FB05) (#1915).
• Remove unnecessary tailed variants for Cyrillic Shha with Descender (U+0527) (#1916).
• Remove unnecessary lower-right serif variants for Latin Lower K with Descender (U+2C6A) (#1917).
• Add italic form of CYRILLIC SMALL LETTER KOMI TJE (U+050F) (#1920).
• Remove unnecessary serifed/tailed variants of italic Cyrillic Te with descender (U+04AD) and m with palatal hook (U+1D86) (#1926).
• Remove unnecessary bottom-right serifed variants of Cyrillic Ka with descender (U+049A..U+049B) (#1927).
• Fix two off-center APL Quad characters in Quasi-proportional (#1930).
• Refine shape of U+0184, U+0185 (#1938).
• Determine serifs of Bulgarian/Serbian De automatically when g is double-storey.
• Fix variant assignment of cv51 for ss03 under italic slab.
• Fix variant assignment of cv31, cv36, cv46, cv47, cv48, cv49, and cv51 for ss18 under italic slab.