S3 update

Now compiled for compute 3.0/3.5/5.0/5.2 and should provide a very healthy hashrate boost for the 900-series.

Apparently R2 and R3 don't work on compute 3.0 cards. Might be the case with 3.5 cards too, haven't had any reports either way though.

The alt build is reported to work on compute 3.0 and should still support all the other levels, that would probably be the best one to start with.

Quick and dirty S3 hash release

Win32 binary, built with CUDA 6.5 so you'll need a fairly recent driver. Intended as a "use until someone makes a better one" kind of a release.