Genie:  Reuse struct tms for CPU times
Genie, relix:  Make accounting timestamp global

Since only one thread is actually running at once, there's no benefit to
per-process instances of the CPU time accounting checkpoint.  It remains
current until a new thread resumes, at which point it's set to the value
of clock(), and it's not queried for other threads.
Genie -> relix:  Make CPU time clocks per-process

Store CPU time accounting data per-process rather than per-thread.
Genie -> relix:  Move times() system call
Merge branch 'times'