ncurses 6.2 - patch 20201024

ncurses 6.2 - patch 20201024

+ provide workaround configure-check for bool when cross-compiling.
+ fix a potential indexing error in _nc_parse_entry(), seen with
  Herlim's test data using address-sanitizer.
+ change a null-pointer check in set_curterm to a valid-string check,
  needed in to tic's use-resolution work pad_char is cancelled
  (report/testcase by Robert Sebastian Herlim)
+ improve tic's -c option to validate the number and type of parameters
  and compare against expected number/type before deciding which set of
  parameter-lists to use in tparm calls (report/testcase by Robert
  Sebastian Herlim).
+ fix a link for tabs.1 manpage in announce.html.in (report by Nick
  Black), as well as some fixes via linklint.