Or at least, directories get generated, signed, download, and checked, with
nobody seeming to crash.

In config/*, added 'signing-key' blocks to dirservers and routers.or, so
that everyone will know about the directories' signing keys.

In or/directory.c, refrained from using a dirserver's signing key when
no such key is known; added more debugging output.

In or/main.c, added debugging output and fixed a few logic errors.

In or/routers.c, added debugging output and prevented a segfault on
routers_resolve_directory.  The interleaving of arrays and lists on
routerinfo_t is still messy, but at least it seems to work again.


svn:r278