Merge branch 'maint-0.2.1' into release-0.2.1

changes/check-fetched-rend-desc-service-id

changes/check-public-key-exponents

src/common/container.h

src/common/crypto.c

src/common/crypto.h

src/common/di_ops.c

src/common/di_ops.h

src/or/directory.c

src/or/dirvote.c

src/or/networkstatus.c

src/or/or.h

src/or/rendcommon.c

src/or/routerlist.c

src/or/routerparse.c