Signal, event and bicycle

[Michael]

> From a quick glance at your code, I believe you are using the 
> hooks wrong. In particular, what's the purpose of:
>
>  this.attachOnDestroy(&onSelfDestroy);
>
> ?

It prevents InvalidMemoryOperationError when in different cases 
observer or observable not destroyed manually;

Also it is was implemented in such way because I can change a 
strategy of event emitting. Yes, may be it was written in 
completely wrong way.

Once again it was an experiment ;)