feat(ao): Timeouts for coroutine functions

[martonlederer]

In #360, timeouts for handlers is discussed. This feature would also be useful for any coroutine related function, such as ao.send().receive() and ao.spawn().receive(). Basically, the execution would error once the deadline is reached, making these functions able to effectively "expire".

Additionally ao.send().onReply() and ao.spawn().onReply() could also be extended to include support for timeouts, once #360 is implemented, since all these two functions need to do is to forward the timeout to the handler they create.