[tabs] forward url parameters to lazy tabs views If http://www.cubicweb.org/project/foo?x=12&y=13 dislays a LazyTabView, this patch forwards {x: 12, y: 13} to subsequent lazy tabs (i.e. called through ajax queries).

if not rql('CWConstraintType X WHERE X name "RQLUniqueConstraint"',
           ask_confirm=False):
    rql('INSERT CWConstraintType X: X name "RQLUniqueConstraint"',
        ask_confirm=False)