Allow for timeouts when expecting values from channels

[cgrigis]

In many places (e.g. here, here, here, here, here, here), the code waits for information on a channel, but does not allow for a timeout. As this information is provided by other nodes over the network, the information will never come in case of crashes, and the goroutine will be stuck forever.
Allowing for a timeout in a select statement will make the code more fault-tolerant.

[JoaoAndreSa]

pull request #29 should address/fix this issue