Committer: Zhuofei Wang <semigodking@gmail.com>
Changes:
1. Modified registration of SIGUSR1 to prevent segment fault on MIPS openwrt.
2. Introduced mechanism of self monitor to recover from hang process.
3. Introduced a new type of method 'direct' which relays incoming traffic out
   directly by default route and default interface. This method is useful to
   users whose ISP limits network connections from different computers.
4. Introduced a new type of method 'autosocks5' which by default relays
   incoming traffic out directly by default route and default interface. In
   case relay connection is closed/reset immediately by remote/GFW, redsocks
   then relays the traffic to SOCKS5 proxy. By doing this, most of traffic
   can be relayed without going through proxy. But, for those connections
   blocked by GFW can go through proxy automatically.