Delete instance method

Hi,

I've written some code in Python for Breve 2.6 in which the method deleteInstance() is called many times to remove certain object types from the simulation.

But in version 2.7 it does not seem to work. Although the instance is "deleted", its graphical representation remains on the screen. The same happens if you try to remove an object from the environment selecting it manually.

Perhaps a bug?

Cheers,
Cesar