Merge pull request #446 from NetLogo/fix-life-err-on-draw

Life: Disable draw button until setup is pressed

Author: jzkelter

Sample Models/Computer Science/Cellular Automata/Life.nlogox

@@ -82,7 +82,7 @@ you can add or remove
 cells by holding down
 the mouse button
 and "drawing".</note>
-    <button x="9" y="138" height="35" disableUntilTicks="false" forever="true" kind="Observer" width="103">draw-cells</button>
+    <button x="9" y="138" height="35" disableUntilTicks="true" forever="true" kind="Observer" width="103">draw-cells</button>
     <input x="119" multiline="false" y="328" height="60" variable="fgcolor" type="color" width="155">123.0</input>
     <input x="119" multiline="false" y="390" height="60" variable="bgcolor" type="color" width="155">79.0</input>
     <button x="11" y="221" height="38" disableUntilTicks="true" forever="false" kind="Observer" width="103" display="go-once">go</button>