multiple lines in a buffer are sent automatically upon a paste
multiple lines in a buffer are sent automatically upon a paste, which can result embarrassing or at least unwanted side effects
Introduce multi-line editing for the inputline
This introduces the new MultiLineEdit that basically enhances the old InputLine widget by being
able to expand to show more than one line. All non-editing related things have been moved out of the
MultiLineEdit to ease reuse in other widgets. For example, InputWidget-specific keypresses are now handled
in InputWidget rather than MultiLineEdit.