Document the current organization and helper functions used to implement the sleep queues used by msleep/wakeup and friends.
Document the current organization and helper functions used to implement
the sleep queues used by msleep/wakeup and friends.

Submitted by:	sheldonh

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase