Show basic statistics

[GoogleCodeExporter]

Show basic statistics (not yet splitted on any attribute like grid size or 
complexity) to try out which figures look nice:
 * A pie diagram showing number of unsolved games (games started but not yet solved) versus the number of games solved.
 * Numbers of games started versus solved per week (historical)
 * Cumulative hours played (historical)
 * Fastest solved game:
    - Preview
    - Date started, solved
    - Number of moves / undo's

Original issue reported on code.google.com by paul.din...@gmail.com on 5 Apr 2013 at 2:03

[GoogleCodeExporter]

Basic statistics for the current game have been added in revision228.

Original comment by paul.din...@gmail.com on 10 Apr 2013 at 8:52

• Added labels: Type-Enhancement
• Removed labels: Type-Defect

[GoogleCodeExporter]

Original comment by paul.din...@gmail.com on 4 Jun 2013 at 8:11

• Changed state: Fixed

[GoogleCodeExporter]

Unfortunately the issue has not been verified explicitly by an independent 
tester.

Original comment by paul.din...@gmail.com on 8 Sep 2013 at 10:48

• Changed state: Verified