Register event on document (example: ModalWindow on greyed-out background)

[sfisol]

1. Allow to register events on document, which will allwo to crete popups dismissed by clicking anywhere outside.

2. Then add new example:

similar to example/trafficlights that will show some static content with a button.

After clicking the button, all is grayed-out, and a modal window appears that ca be closed with an OK button or by clicking outside (maybe 2 examples)