"addDestroyCallback" in pin behavior

I'm interested in "addDestroyCallback" in pin behavior.

I found that each pin behavior will push a function object to runtime's "destroycallbacks" array through "addDestroyCallback". Function object array "destroycallbacks" will be executed when each object destroyed.

When pin behavior had been destroyed, the callback in "destroycallbacks" will never been removed.

If I create many many pin behaviors, these might insert many many function objects into "destroycallbacks" array and never remove it. It's not a bug, just a little ... drawback.

Oops, you're right - this is actually a small memory leak. I've added a 'removeDestroyCallback' for the next build and updated all behaviors that use it to also call that when they're destroyed. Thanks for the heads up!

"DestroyCallback" or "CreateCallback" may be useful in plugin.

For example, maintain a hash table to get instance from uid directly.