That's just a binary which you're welcome to upload to the S5 and better than bitmain's default one, having fixed a few glaring problems, but there's no comprehensive rewrite of the code like there was for S1-S3 by Kano.
I was just looking for instructions on how to do that.
use winscp to connect to your S5 (root/admin)
navigate to /usr/bin
rename cgminer to cgminer.480 (always a good idea to keep a backup...)
copy the new cgminer to /usr/bin
set properties to 0755
disconnect
open your S5 web interface
go to miner configuration
clic save and apply (to restart cgminer without changing config)
done