feat(user/bkfeh):Ignore dotfile directories (e.g. `./.Photos`)

- feat(unitproc/bkt-filter_no_dots):Add bash function to filter out
  stdin lines with dotfile basenames. (Note: Quite slow).
- chore(unitproc/bkt-read_stdin_psarg):Remove debug code and fix how
  posarg is read (error found via shellcheck).