data structures. Makes it easier to use pthreads too.
Still need to add code for non-pthreads systems.
Just a checkpoint to switch work to another machine.
Move libfmt, libutf into subdirectories of lib9.
Add poll-based socket i/o to libthread, so that we can
avoid using multiple procs when possible, thus removing
dependence on crappy pthreads implementations.
Convert samterm, acme to the single-proc libthread.
Bring libcomplete, acme up-to-date w.r.t. Plan 9 distribution.
