v0.50.8

Improvements

• The Symbols keyboard is now a top-level keyboard. Previously it was accessible
  only from the Roman keyboard.
• Added some standard Latex commands: \inf, \Pr, \liminf, \limsup
• Added inline shortcuts for some commands: sinh, cosh, sec, csc,
  cot, arcsin, arccos, arctan
• When generating Latex output, only insert spaces when necessary (i.e. after
  commands that are followed by a letter). Conversely, always generate the space
  when necessary (\rbrack a would generate \rbracka)
• Minor rendering performance improvement

Bug Fixes

• The absolute value character "|" (and other small delimiters) would be
  displayed in the wrong font (and too small)

• The absolute value key from the virtual keyboard would
  insert '|#@|'

• The 'sqrt' key from the virtual keyboard or keyboard shortcut
  (option+V) would do nothing. The problem affected any inline shortcut or key
  that included a '#0' argument when there was no selection

• Fixed an issue with long inline shortcuts that could trigger text mode
  (e.g. 'arcsin') and never apply the inline shortcut

• Do not trigger smart mode conversion with arrow keys

• Fixed an issue on iOS 12 and Firefox/Android where the Mathfield could not be
  focused (fix contributed by (https://github.com/beneater)