The `die` in the pipe does not exit the whole script but only the pipe.
This currently works because the pipe is the last thing being executed.
If something would come after the pipe, the hook would happily continue
executing. Properly propagate the exit to prevent this in the future.
The function `die` was redundantly implemented in various files.
Move the function into .local/bin/helpers.sh and source that where
previously implemented.
Also prepend the program's name to the message and always terminate the
message with a newline. The newline was previously needed for a small
but unnecessary hack that prevented the need of the `[ -z "$1" ]` test.
Refactor the script to match my coding style more and update the
comments.
When checking the filenames for non-ASCII characters, check also
renaming of files instead of only additions.
