Merge remote-tracking branch 'origin/maint-0.2.4'

changes/bug6174

src/or/circuitbuild.c

src/or/circuitlist.c

src/or/circuitlist.h

src/or/circuituse.c

src/or/circuituse.h

src/or/config.c

src/or/connection_edge.c

src/or/main.c

src/or/or.h

src/or/relay.c