Helper program: notify

Sends an event to a process.  You must control the process to be able to
send an event (everyone controls everything, for the most part), and the
process must have an event handler registered.  Similar to 'kill.'

This is similar to the kernel monitor command 'notify', except this has
payloads and that can bypass the event registration table.
BCQ touch-ups (XCC)

Weren't memsetting the entire structure, and I wasted an hour or so
debugging a BCQ with a non-power-of-2 number of elements.

Reinstall your kernel headers.
Updates get_html

Can handle non-port-80 ports and will request a connection close after
the one request.
Fixes loopback checksums

The packet checksum finalization wasn't being performed for loopbacks,
preventing us from making any loopback connections.
Helper, check for the existence of local RKMS

For the local core only.
vcore_idle(): halts a core

MCPs can halt their cores, waiting on an interrupt.  An event sent to an
event queue with EVENT_IPI is sufficient to wake a vcore.  Other IRQs or
races can result in wakeups, either from a fresh vcore context or by
having vcore_idle() return.