Undo history cleared when rotating screen

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Enter a number on the game board. Note that the undo button appears. 
2. Rotate screen. Observe that the undo button disappears. 
3. If you enter a number at this point, the undo button reappears and you can 
use it to undo the last action, but you cannot undo anything from before the 
rotation. 

I expected the undo button not to disappear when I rotated my phone. 

What version of the product are you using? On what device and Android
version?
Holoken 1.2 on Android 4.3 on Nexus 4.

Original issue reported on code.google.com by jonat...@basseri.com on 10 Nov 2013 at 7:26

[queler]

definately a bug