This branch uses the gaps patch from: http://infra.in.zekjur.net/pipermail/i3-discuss/2012-November/001042.html
I have also included some minor fixes that, for me at least, makes it work perfectly.
As well as this there is now a little bit more convenient way to change the gap size by modifying the GAP_SIZE macros near the top of src/render.c .
And the result: (click the image below to see a video of it in action)