One Window UI
this will not be the default. nonetheless some people like this design (tkabber, jbother and others).
so we will expose this in General tab under Preferences.
I did a proof-of-concept (or a bit more than that actually) that one can use to fight bugs, test and extend.
note that we cannot reparent the WINDOW itself, so I go for the notebook.
See attachments
ps. Travis, what is the alignment in msg_window before notebook is doing there. is it left over?