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