Document most undocumented variables.

src/common/util.c

src/or/command.c

src/or/config.c

src/or/control.c

src/or/directory.c

src/or/dirserv.c

src/or/hibernate.c

src/or/main.c

src/or/networkstatus.c

src/or/or.h

src/or/relay.c

src/or/router.c

src/or/routerparse.c

src/or/test.c

src/or/test_data.c

src/or/tor_main.c