Updated tree:

Attribute correct GPU for accepted/rejected shares.
Check again that block hasn't gone stale if trying to resubmit after failed submit.
Make failure to load binary kernel go back to building from source instead of failing to initialise that GPU.
Increase gpu thread count back to 2 by default now that stale block control is more robust. This gives a demonstrable throughput benefit.

Currently working on: Incorporating windows build magic from Ycros (thanks!)

TODO:
Increase buffered work to configurable number instead of just 1 and perhaps default to 2.
Look at those other new kernel changes pointed out by znort987 (thanks!).