Merge branch 'rs/grep-binary'

Merge branch 'rs/grep-binary'

* rs/grep-binary:
  grep: support NUL chars in search strings for -F
  grep: use REG_STARTEND for all matching if available
  grep: continue case insensitive fixed string search after NUL chars
  grep: use memmem() for fixed string search
  grep: --name-only over binary
  grep: --count over binary
  grep: grep: refactor handling of binary mode options
  grep: add test script for binary file handling