Merge branch '2020wk13' of https://github.com/kerolasa/util-linux

Merge branch '2020wk13' of https://github.com/kerolasa/util-linux

* '2020wk13' of https://github.com/kerolasa/util-linux:
  include: add remove_entry() to env.h
  tests: add sanitize_env() check
  more: fix moving backwards so that it can reach begining of the file
  more: use getopt_long() to parse options
  more: remove underlining related code
  more: fix SIGSTOP and SIGCONT handling
  more: make execute() more robust and timely
  more: target all standard streams when calling fflush()
  more: remove kill_line() in favor of erase_prompt()
  more: avoid defining special characters locally
  more: use off_t and cc_t to clarify what variables attempt to represent
  more: do not reset parent process terminal in execute()
  more: use single exit path to ensure resource freeing is unified