ion lets the user specify which keys to use for game control.
Valid keys are: Any character or any special key which synonym is displayed
in the separate popup window. Any of these synonyms can be specified.
<li><b>Current keys</b><br>
This option shows which keys are currently used for game control.
</ul>
<br>
<li>The <b>Bricks</b> menu<br><br>
<ul type="disc">
<li><b>Add brick</b><br>
This option lets the user add a user defined brick to the game by loading it
from a file created with the editor which is 