Destruction of objects

[migueldeicaza]

Currently every finalizer queues an execution on the main thread of the unrefing of the object, we should instead queue all of these in a batch, and then dispose those in one go.

[EgorBo]

InvokeOnMain actually adds an action to a list of actions to execute and once the next frame appears - it does foreach over the list and executes all the actions. The only way to optimize it is to do a single pinovoke DeleteNative(IntPtr[]) instead of multiple DeleteNative(IntPtr)