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.
