Followup to #16 which introduced the --err-skip-line-length option to totally disable the "very long lines" error:

--err-skip-line-length is useful to avoid being spammed when many files ave too large lines to be searched.

However, it's dangerous to use this option: it completely silence the fact that some files were skipped because of their size.

To fix this, I suggest to print a one line error, at the end of the sift execution, when at least one file was skipped because of its size (maybe with a skipped file counter).

This would both avoid the spam (one line is not a spam, and if it is, we could have another option to really disable all of this, as it's currently done), and still inform the user that some files have been skipped: if the user wants full results, it could disable the option, or change the blocksize limit, as explained in the current error log.