add timeout parameter

[wellenvogel]

I propose to add a timeout parameter to redsocks.
usage Scenario:
When using redsocks to also redirect naming resolution (DNS) via forward of udp port 53 to the built in DNS responder (with forcing redirect to tcp), the resolver get's a bit confused when the remote host is unreachable as it is able to connect but times out on send/receive. This leads to long timeouts when using DNS resolution (with no chance to lower them by resolver settings).
With an additional timeout option we can easily configure a second redsocks section in the config file using an own port only for DNS forwarding and applying a timeout value there.
Example:
iptables -t nat -I REDSOCKS -d 0.0.0.0/0 -p tcp --dport 53 -j REDIRECT --to-ports 12346
and in the config file (beside the normal forwarding stuff):
redsocks {
local_ip = 127.0.0.1;
local_port = 12346;
ip=...
port=....
....
timeout = 1;
}