Directory search isn't returning any files in search results

In trying to integrate the beta version of 6.2 with the regular core search results, I wasn't seeing any files from the directory search returned. Looking at the code, I could see that the search was looking in a table called search_directories_files, but the table itself wasn't being populated. However, search_files_files still was, and with the exact information that was to be stored in search_directories_files. The patch I'm including changes all the references to search_directories_files to search_files_files. After I applied those changes, I got the search results I expected.

I'm not sure if the development team was wanting to move over to the search_directories_files table, or stay with search_files_files, but please feel free to include this patch if you'd like.

Great work on this module, by the way. I can't wait to see the next release.

Thanks!