Remove most unused references to CONFIG_NET_MULTICAST.  Rename other uses of CONFIG_NET_MULTICAST to avoid naming comflicts.

TCP poll: TCP poll events can really only being processed when the poll from the correct device is received.

TCP timeouts: Fix some logic when there are multiple network  interfaces.  In this case, TCP timeout events can really only being processed when the poll from the correct device is received.

Cdcacm_rd_wr_confusion

drivers/syslog/note_driver.c:  Add a driver that will allow an application to read buffered scheduler instrumentation data

Move scheduler instrumentation hooks out of sched.h (where they seem like application interfaces) and into nuttx/sched.h where it is clare that these are OS internal interfaces.