Adding a context to the remote for shutdown.

[perbu]

one major change. engine.WithRemote now takes a context, which is passed to the remote. It will shut down the remote when the context is cancelled.

one minor change. The engine now has a GetLogger() which responds with the logger, so the remote can set up logging on its own. previously you had to supply a logger directly to the remote, which is cumbersome and error prone.

I've tried and failed to avoid adding another method to the engine to do this. The alternative would be to make the remote package internal, meaning the user would not be able to import the remote package directly.

trivial changes:

• The make files now also builds the examples using the remote.
• the log package contains a Debug() which returns a logger with debug level preset. Useful when developing tests.
• I've also tried to document some functions which had missing or imcomplete docs.

Todo: Since the remote now can be shut down, how should the remote behave in it's shutdown state? Should it have a flag indicating that it is still active? Should it panic when somebody tries to use it? Please advice.

Todo: When expanding on the tests to check that we actually stop listening to the socket I didn't find a nice way to figure out if the remote has completed cancelling the remote. Any ideas here? cancel() is async so it might take a few microseconds. It seems to work on my computer, though, syscalls are slow, I guess.

[perbu]

@anthdm I think this is ready to be merged now. I'm resonably happy with it. Let me know if there anything you wanna change and I can adjust it.

[anthdm]

@perbu This is going to be a fun conflicting resolve session for you, huh? xD

[perbu]

conflicts resolved. ready to merge.