described in <a href="http://lww.CS.Arizona.EDU:80/~henriks/editor.html"><b>Brick editor</b></a>.
This can also be acheived by the keyboard shortcut <b>meta-a</b>.
If the brick is added successfully, the user is given an id for the brick
which should be used if the brick is going to be removed from the game again.
The added brick will appear in every game from here on until it is removed or
the application is closed.
<li><b>Remove brick</b><br>
If any user defined bricks are currently in the game, this opti