This reverts commit 6ddd4f019f since it
breaks AppImage builds. The newer version of QScintilla depends on Qt
5.11 which is not available in the Ubuntu 18.04 the AppImages use. We
also cannot just use the version of QScintilla available in the OS
instead of the bundled one for the AppImages as that is too old for our
purposes. It is probably best to just update to Ubuntu 20.04 for the
AppImage builds in April 2023 when 18.04 reaches its end of life.
This is a first rough implementation of QScintilla support as SQL text
editor.
It should work mostly and build fine with qmake as well as cmake. The
new code supports all the features of the old one plus adding a few
subtle improvements. The main point of this, however, is reducing the
code we have to maintain and making it easier to add new features to the
editor.
Martin Kleusberg