Log Message:
zile: Update to 2.4.15

* Noteworthy changes in release 2.4.15 (2020-11-05) [stable]

** Bug fixes

  Ensure term.h matches [n]curses[w].h (fix #58880).

  Fix a potential crash in the Lisp “interpreter”.

  query-replace no longer prints the number of replacements on error.

** Build-related

  Various improvements and fixes, including updates to gnulib and bootstrap,
  improvements to the build instructions, and the removal of obsolete files.

  Use automake’s parallel test harness to run the tests.

  Make running the tests with Emacs optional. A lot of them do not pass any
  more with recent Emacsen, but this is not an urgent problem.

  Use ASAN instead of Valgrind for memory checking: this makes the tests run
  much faster.

  Remove the use of texinfo markup from docstrings.

  tbl_vars.h no longer needs to be generated from tbl_vars.h.in, as no
  substitutions were being made.

** Miscellaneous

  Some code clean-up, including a simplification to the calling convention
  for C functions that implement editor commands.

  Update some docstrings to match Emacs 27.1.