scide: GenericCodeEditor - backspace in overwrite mode should insert a whitespace

Signed-off-by: Tim Blechmann <tim@klingt.org>
scide: GenericCodeEditor - force redraw when toggling the override mode

Signed-off-by: Tim Blechmann <tim@klingt.org>
scide: main window - pass settings as argument to applyCursorBlinkingSettings

Signed-off-by: Tim Blechmann <tim@klingt.org>