Log Message:
Update to 2.13.0.0. From the changelog:

- New functions: buffer_timed_put(), buffer_timed_puts(), for
  synchronous writes to a file descriptor with a time limit.
- strerr2.h deprecated. strerr.h entirely revamped. Every existing
  strerr interface is now a variable argument macro around the new
  strerr_warnv, strerr_warnvsys, strerr_diev and strerr_dievsys
  functions, which just prints arrays of strings to stderr. This reduces
  the amount of adhocness in the strerr code considerably, allows calls
  without an upper bound on the number of strings, and should save some
  bytes in resulting binaries.
- librandom revamped (again).
  * random_init() and random_finish() removed.
  * random_char() removed.
  * random_string() renamed to random_buf().
  * early versions added.
- New djbunix functions: waitn_posix(), waitn_reap_posix().
- readnclose() made public, now doesn't touch errno on success.
- openreadnclose_at() now returns a ssize_t.
- Bugfixes.