Move the connect for updating the line number area width from the reload
settings method to the constructor to make sure it's only called once.
Otherwise there would be more and more unnecessary connections made
whenever the settings are reloaded.
If a syntax error is reported by SQLite during execution in the Execute
SQL tab of the main window try to locate the problematic SQL statement
and highlight it using a red squiggling line.
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.
Any SqlTextEdit object has its SQL syntax highlighter anyway, so it
makes sense to move the syntax highlighter object inside the text edit
class instead of maintining somewhere else. This hopefully makes the
code a bit easier to maintain.
Add two new settings to allow changing the font size inside the SQL log
and the SQL editor.
Increase the default font size from 8 to 9 - better a bit too big on
some systems than too small on others.
Also do some restructuring in the MainWindow to avoid duplicate code to
reload settings.
Remove some useless debug messages, e.g. because they just print an SQL
string which you can see in the SQL log window anyway.
Change some "critical" errors messages to just warning. No sense in
printing a critical error message when the program can handle the
problem by itself.
