Adding more flexibility to enter lines of bricks in the levelset. Possiblities are now
<Line>112211</Line>,
<Line Bricks="112211"></Line>,
<Line Number="1">112211</Line>
and
<Line>
<Number>1</Number>
<Bricks>112211</Bricks>
</Line>
Combinations of these are also possible. When no line number is given the line number is increased by one. That means successive lines don't need a line number on every line.