Provide flag to show only files that were skipped

It is as important to know what files were skipped (by configuration) by a scan as this means these files MUST be listed as compliance exceptions for the ASF. In addition, people forget to add file extensions to the .cfg file (e.g., .html, *.css, etc.) and we have many files that are used for configuration in formats that are permitted to be excluded, but should be accounted for (e.g., *.xml, *.json, etc.).

It would be my recommendation to not files that are skipped, by extension, for those files that have extensions (or no extension) that are skipped.