cli 3.6.4

• Pluralization now handles edge cases (NA, NaN, Inf and -Inf)
  better (@rundel, #716).

• The URI generated for .file, .run, .help and .vignette hyperlinks
  can now be configured via options and env vars (@jennybc, #739, #744).

• cli_progress_bar() now accepts total = Inf or -Inf which mimics the
  behavior of when total is NA (@LouisMPenrod, #630).

• num_ansi_colors() now does not warn in Emacs if the INSIDE_EMACS
  environment variable is not a proper version number (@rundel, #689).

• ansi_collapse() and inline collapsing now uses last as the separator
  (without the serial comma) for two-element vectors if sep2 is not
  given (@rundel, #681).

• ansi_collapse() is now correct for length-1 vectors with style "head"
  if width is specified (@rundel, #590).

• New hash_xxhash() etc. functions to calculate the xxHash of strings,
  raw vectors, objects, files.