Change to BadExit logic: Let authorities set an "I list bad exits" flag. Consider an exit bad if it is listed as bad by more than half of *those* authorities. This gives us a better migration path.
svn:r8756
Add client support for a 'BadExit' flag, so authorities can say "Server X is a poor choise for your nytimes.com connections, as it seems to direct them to HoorayForMao.com or (more likely) WouldYouLikeToBuyTheseFineEncyclopedias.com"
svn:r8690
Disprefer exit nodes for entry, middle positions (fixes bug 200). Also, switch to using a uint64_t to hold "total bandwidth for all nodes" under consideration; crypt_rand_int would have died at 2GB/s network capacity.
svn:r8571