[Etoys] [fix] PasteUpMorph shall not accept ScriptEditorMorph version 3

[Karl]

Yoshiki Ohshima wrote:
>
>   * [fix] PasteUpMorph shall not accept ScriptEditorMorph (version 3)
>
>     This was also a feature.  Think Takashi's Demon Castle tutorial.
>     This one and the other one has upside and downside, and not
>     entirely obvious whether to be included or not.
Thinking about this a little I remembered that we have a preference that 
deals with this issue : systemWindowEmbedOK
Before the preference was introduced all menus and SystemWindows would 
embed into PasteUpMorphs etc.
What do you think of using the preference on ScriptEditorMorphs as well, 
I think they are a kind of SystemWindow and
it would be possible to change setting when one really wants to embed 
the ScriptEditorMorph. Maybe one wants to embed some menus and 
SystemWindows in the future as well and the preference is then already 
set for you :-)

Karl