semaphores

I've been doing some more work on the microkernel and have got to the point where a user-mode application can create other processes and threads, get its priority and so on and also - semaphores!

They're counting semaphores with support for priority inheritance. Unfortunately it's still a basic round-robin scheduler so it's a little harder to test it yet but hopefully soon it'll be possible to work on some more posix-like code to try and support some BSD style services or networking like Lwip.

Of course, the driver model needs to be tweaked first as the rather limited kernel mode drivers need to be updated & IPC needs to added support user mode drivers.