[Toybox] ps and top (and Android)

[enh]

re: https://github.com/landley/toybox/commit/529d5db29a32db565d2ee0aeac133e47ec045e12,
note that we're not switched over because neither ps nor top have
thread support. everything on Android is threaded except init, so
people would notice :-)

there are a bunch of little things too that i can send patches for,
but the thread support seems like a more architectural thing so i was
waiting to see what you were going to do. (not least because GNU ps
has three or four different modes for showing threads, their 'H' being
closest to the Android -t.)