Commit Briefs
various little changes.
also pick up latest fltfmt from plan 9
cleanups - lots of removed files now in thread library.
qlock.c - stubs to thread library notify.c - clean interface slightly.
better unwinding for 386.
command-line extraction from core files on linux and freebsd. move linux ureg into ureg386.h (used in many places).
help for libthread_db (define ps_prochandle)
add symbols to unwind for disasesmbly-based stack unwinding add global state for library to help debugger programs (symhdr etc., attachproc, attachcore, attachargs).