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