Fix for gdbstub argument change in qemu 0.11.  Rename qemu-gdb-nox target to qemu-nox-gdb because you frequently want to add the gdb part, but rarely the nox part.

(maybe this never worked, but it works now)

locks were moved around.

this time do it ourselves instead of piggybacking on TLS.
add -fno-pic to Makefile; pic code breaks our fake TLS.

 * rename c/cp to cpu/proc
 * rename cpu.context to cpu.scheduler
 * fix some comments
 * formatting for printout

pdf has very good page breaks now.
would be a good copy for fall 2009.

Some proc cleanup, moving some of copyproc into allocproc.

Also, an experiment: use "thread-local" storage for c and cp
instead of the #define macro for curproc[cpu()].