Adapt the KINFO library to aggregate per-cpu cputime statistics.

Adapt the KINFO library to aggregate per-cpu cputime statistics.

	(a) add a framework for aggregating per-cpu structures, of variant
	    field types; this interface will undergo change once it is
	    formalised upon, kinfo_pcpu.[ch].

	(b) minor style(9) cleanups while I am around these ends.

	(c) adjust libkcore, this might not be fully correct but it fetches
	    the right symbol at the least, it is not so easy to collect
	    per-cpu statistics from core files without doing magic with the
	    CPU privatespace like how we do in GDB debug scripts.

	(d) kinfo_get_sched_cputime(3) is fetching aggregate statistics to
	    retain behavior, most programs do not care about per-cpu stats
	    without getting really mucky anyway; (discussed with joerg)