Add ability to set hooks without include standard library

[AJBuilder]

This sort of feature is the determining factor making me unable to use this library for my use-case.

I need preemptability— to pause and resume the running script so it doesn't stop the calling c# thread. I can't have one script running user written code to freeze the whole system with an infinite loop. I need to be able to run multiple Lua threads on the same thread synchronously. Run one a little bit then switch.

There is a way to do this with debug hooks. Create a hook that runs every few lines that yields. However, I don't see a way to do this without exposing the debug library to the environment.

In the C implementation, I'm fairly certain it is possible to be able to set hooks without exposing the library. Without this I have to resort to native bindings like NLua.

Unless there is another option for this behavior that I am unaware of?

(Awesome work btw. Excited to try 0.5. Especially this feature.)

[AJBuilder]

Nevermind! I see that the singleton is available in DebugLibrary.cs.

I was looking at the wrong branch. Sorry for the issue.

On that note, is main stable enough to start developing with?