Features

Added Yuta Mori's induced sort
Added the option to select a SuffixSort algorithm
Replaced WriteInt64 with a faster method
Yes, as I said in my pull request and code comments, this is Yuta Mori's SAIS implementation, verbatim.

I have cleaned it up quite a bit in my ttwinstaller repo, which you're welcome to snag if you plan on keeping SAIS.