Remove last vestiges of old logging interface.

src/common/log.h

src/common/util.h

src/or/buffers.c

src/or/circuitbuild.c

src/or/circuitlist.c

src/or/circuituse.c

src/or/command.c

src/or/config.c

src/or/connection.c

src/or/connection_edge.c

src/or/connection_or.c

src/or/control.c

src/or/cpuworker.c

src/or/directory.c

src/or/dirserv.c

src/or/dns.c

src/or/hibernate.c

src/or/main.c

src/or/onion.c

src/or/or.h