rewrite doc/benefits.html
rewrite doc/index.html
add doc/uselsb.html
have sv replace runsvctrl, runsvstat, svwaitdown, svwaitup
rewrite doc/dependencies.html: weak/string deps
runsv: provide ./run's return code to ./finish, count startups of ./run and
  provide number to ./run
chpst: -u user[:group0[:group1 ...]]