Add Condition<SElement> for <table> element: Have.Rows(params string[]) & Have.NoRows()

[yashaka]

usage examples:

S("table").Should(Have.Rows(
    new [] {"Row1 columnA", "Row1 columnB"}, 
    new [] {"Row2 columnA", "Row2 columnB"}
);

//...

S("table").Should(Have.NoRows());