Support of busytimeout in sqlite3 plugin
Add _endt to WidgetBase.php to solve a bug in datetime form widget.
New method WidgetBase::endOfTag() for jForm widgets

Refs #169
Vagrant configuration to test jelix <= 1.6.x
jForms - error decorator should erase list at verification start

After a second try of submit, error messages are still there. It is
annoying if the form is submitted with ajax.