when content of table Ophaalpunten changed, reload Completers (part 4)

fixed typo in Signal-Slot connects. Should work now
Patch for Issue #1

I added _a_ _lot_ of qDebug() statements so to find future bugs for this
sort.

Basicly I skipped codeline `QObject::disconnect(c, 0, this, 0);` from
MyLineEdit::setCompleter(MyCompleter *completer)

Up to now, the bug hasn't been happening anymore. Are there any
consequences??