Fixed quit crash

[R4H33M]

Fixes #36

Took quite a lot of detective work to get this one down. I was able to trace the issue to BWindow::Quit();.
The issue stems from BScrollView's BScrollBars, which is improperly deallocated due to the TakeNote's special usage of NoteView, indeed, the problematic object is a child of BNoteView.

By calling a RemoveSelf on the NoteView, as advised on this page of the legacy docs: https://www.haiku-os.org/legacy-docs/bebook/BView.html, we prevent the crash and let's the program quit cleanly.

Edit: tested on both x86_64 and x86 (gcc2)

[pulkomandy]

The fix does not look right to me. It is expected that a window owns all its views and will automatically delete them. If that does not work, the solution is not to remove the view from the window so that it is never deleted, the solution is to fix the view so that deleting it will work.

[R4H33M]

To keep things clean, I have made a separate PR for my latest potential fix to issue #36
It is here #49
Thank you for your advice @pulkomandy. When fixing bugs/crashes, it is important to really fix it from the real root of the issue.