We already let enter/return key presses to reach text edits instead
of closing the editor. Do the same for tab/backtabs.
[ChangeLog][QtWidgets][Important behavior changes] QItemDelegate will
now not close a QTextEdit/QPlainTextEdit editor when the tab key
is pressed; instead, the key will reach the editor.
Task-number: QTBUG-3305
Change-Id: Ife9e6fdc5678535c596d1068770b0963134d8d5a
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@theqtcompany.com>
Reviewed-by: Thorbjørn Lindeijer <bjorn@lindeijer.nl>
Reviewed-by: Thorbjørn Lund Martsum <tmartsum@gmail.com>
84a3dacf46