r15939@catbus: nickm | 2007-10-18 22:14:15 -0400

 r15939@catbus:  nickm | 2007-10-18 22:14:15 -0400
 Remember the valid-until time of the most recent consensus that listed
 a router, and (if we are a cache) never delete the routerdesc until
 that conensus is expired.  This is way easier than retaining multiple
 consensuses.  (Of course, the info isn't retained across restarts,
 but that only affects a few caches at a time.)

svn:r12041