Freezes on bad playlist urls

[andykarpov]

Sometimes (actually - very often) ka-radio freezes (stop playing & stop responding via the web-interface as well as via serial connection). I can reproduce this while switching to the station url that is not responding, such as:

1. DNS server is unable to resolve a given name
2. The radio host did not responding while trying to connecting a given stream socket
3. Probably in some other cases

The first idea how to fix that is to introduce timeouts for:

1. DNS resolver udp connection
2. Stream connection
3. Probably somewhere else

PS: Tested on the latest release 1.9R6.