Some 3DEN related issues

[gippo 38]

1: RegisteredToWorld3den EH is not working at all. Can use init and is3den check though.
2: AttributesChanged3den EH is not working if you use widgets or if you have selected multiple entities (only for one selected entity)
3: I personally still miss the script command to exclude some 3den changes from history. Eg: you change change some attribute on an object, EH set up to change something else accordingly -> user needs to undo 2 times to get back the original state
4: Minor suggestion: Adding an ability to make a scripted 3den change without triggering any Eventhandlers. Can workaround with script, still - I would love to see an engine solution.

Will report them if I find any further issues.