- typo fixes
- sort xrefs
- some other minor cleanup.

for the GPROF4 case.  This allows a simpler method to be used for
non-statistical profiling (it allows overhead adjustments to be
subtracted from one counter without harm if that counter goes
negative; otherwise the adjustment would have to be distributed).

32 bit counters were already too small for GPROF4 with a 200MHz
clock.  int64_t counters should be used.

resolution profiling on Pentiums.  On a 100MHz Pentium, the resolution
is at best 10 ns and actually a few hundred ns, but units of 10's or
100's of ns would be inconvenient and the current units of 1 us are a
bit too coarse.

Down to only about 100 items left to cleanup! :-)

looking at a high resolution clock for each of the following events:
function call, function return, interrupt entry, interrupt exit,
and interesting branches.  The differences between the times of
these events are added at appropriate places in a ordinary histogram
(as if very fast statistical profiling sampled the pc at those
places) so that ordinary gprof can be used to analyze the times.

gmon.h:
Histogram counters need to be 4 bytes for microsecond resolutions.
They will need to be larger for the 586 clock.
The comments were vax-centric and wrong even on vaxes.  Does anyone
disagree?

gprof4.c:
The standard gprof should support counters of all integral sizes
and the size of the counter should be in the gmon header.  This
hack will do until then.  (Use gprof4 -u to examine the results
of non-statistical profiling.)

config/*:
Non-statistical profiling is configured with `config -pp'.
`config -p' still gives ordinary profiling.

kgmon/*:
Non-statistical profiling is enabled with `kgmon -B'.  `kgmon -b'
still enables ordinary profiling (and distables non-statistical
profiling) if non-statistical profiling is configured.

specified in the top level Makefiles.