This breaks "Show menubar temporarily when hidden" when several windows
are open, since signal disconnection by data no longer works as
intended.

Related: !42

427 translated messages.

Transifex (https://www.transifex.com/xfce/public/).

419 translated messages, 8 untranslated messages.

Transifex (https://www.transifex.com/xfce/public/).

427 translated messages.

Transifex (https://www.transifex.com/xfce/public/).

244 translated messages, 183 untranslated messages.

Transifex (https://www.transifex.com/xfce/public/).

390 translated messages, 37 untranslated messages.

Transifex (https://www.transifex.com/xfce/public/).

385 translated messages, 42 untranslated messages.

Transifex (https://www.transifex.com/xfce/public/).

427 translated messages.

Transifex (https://www.transifex.com/xfce/public/).

Bitwise shifts are convenient and inexpensive but obviously too limited
in this case, and integer overflow can be difficult to spot.

Fixes: #165
Related: !109

427 translated messages.

Transifex (https://www.transifex.com/xfce/public/).

427 translated messages.

Transifex (https://www.transifex.com/xfce/public/).

It is deprecated, but just as much as GtkImageMenuItem whose style is
reproduced here, and Xfce still uses it. It was not honored since
Mousepad 0.5.0 and the switch to GMenu, and was not restored in !77.

Regression introduced in ea239c3f and
19ce10e7.

This causes a problem when replacing with an empty string, by then
selecting the first entry in the replacement list, thus preventing
replacing again with an empty string. It also selects the first entry in
the search list when searching for an empty string, which is less
annoying but still a bug.

More generally, there is no reason to re-select the first entry if the
list has not changed.

Related: !119