3DS Max Plugin Update - Lights Switch V2.0

This is an update for the plugin I wrote 6 years ago, called Lights Switch.
The reason behind the update was an e-mail from a user who had a small issue with a scene full of Cororna lights, where the script managed to turn all lights OFF, but for some reason failed to turn them ON again.
After inspecting the script, I recognized the bug and fixed it.

Basically, the script, when clicked, will go through all lights in the scene, and if any light is ON it will turn it OFF. On the other hand, if the script sees that all lights are OFF it will turn them all ON again.