Fix a bunch of typos in various man pages.

add a missing a word

minor tweaks;

bluhm@ suggested pointing out that cpumem_malloc_ncpus and
counters_alloc_ncpus preserve the contents of memory used by the
boot cpu.

bluhm@ suggests that it is enough to say that the allocations will
be zeroed, and how they're zeroed is an implementation detail that
doesnt really help the reader.

start documenting allocating per cpu data at boot time, and adding
memory for new cpus after theyve attached.

some tweaks from jmc@ who will probably find more things wrong after this.
im putting so

start documenting allocating per cpu data at boot time, and adding
memory for new cpus after theyve attached.

some tweaks from jmc@ who will probably find more things wrong after this.
im putting some suggestions in from bluhm@ shortly

show more ...

Add missing dot at beginning of macro line.

more tweaks; ok dlg

provos didnt write any of this

tweak previous;

first cut at a man page for cpumem