The ADIOS server code

Now that we've seen all of the work that goes into the low-level driver, it's time to look at the ADIOS server that uses these drivers.

At the highest layer of abstraction, ADIOS creates a shared memory segment and periodically polls all of the installed drivers for their analog and digital data before sticking it into shared memory.

ADIOS has two threads: one thread handles the resource manager side of things, and another thread handles polling the individual drivers. This approach was taken because I didn't want the polling thread to bog down the responsiveness of the resource manager. However, this is a moot point, because the resource manager currently doesn't actually do anything. I provided a resource manager interface for future compatibility in case we needed a way of changing the sampling rate (for example), but there haven't been any requirements to do that.