TODO

Things to do:
- Document Hound design, including core, drivers, and schemas
- Add queue stress tests.
- IIO automated unit tests, using the kernel dummy IIO driver
- GPS automated unit tests, automatically starting up gpsfake from the gpsd
  distribution.
- IIO driver dynamically listing sysfs entries and doing string parsing to
  figure out possible channels (like iio_generic_buffer does), instead of
  hardcoding these.
- Optimize drv_alloc, since both record data and struct record_info are
  short-lived.
- Audit logging to make it consistent throughout the code.
- Add a statistics API that would surface information about driver record
  allocations failing, queues overflowing, etc. The theme is that the I/O and
  queue code has no way to surface errors to the user, so they currently just
  log that information and it's not programmatically discoverable.