torcontrol improvements and fixes

- Force AUTHCOOKIE size to be 32 bytes: This provides protection against
  an attack where a process pretends to be Tor and uses the cookie
  authentication method to nab arbitrary files such as the
  wallet
- torcontrol logging
- fix cookie auth
- add HASHEDPASSWORD auth, fix fd leak when fwrite() fails
- better error reporting when cookie file is not ok
- better init/shutdown flow
- stop advertizing service when disconnected from tor control port
- COOKIE->SAFECOOKIE auth

src/net.h

@@ -131,6 +131,7 @@ bool IsLimited(enum Network net);
 bool IsLimited(const CNetAddr& addr);
 bool AddLocal(const CService& addr, int nScore = LOCAL_NONE);
 bool AddLocal(const CNetAddr& addr, int nScore = LOCAL_NONE);
+bool RemoveLocal(const CService& addr);
 bool SeenLocal(const CService& addr);
 bool IsLocal(const CService& addr);
 bool GetLocal(CService &addr, const CNetAddr *paddrPeer = NULL);