- Changed the value-list on the left to use the symbols from the theme instead of old hardcoded symbols
- Removed old code for symbols as it will not be used anymore and had bad usability

I consider the old behavior as a showstopper-bug, as it may result in completely different symbols in the game and the list
If this fix results in new problems, please undo this commit

svn path=/trunk/KDE/kdegames/ksudoku/; revision=894750