More small improvements

Sumaddle version 1.38.0 contains some small corrections and enhancements. The changes in detail:

• The page showing the outcome of a puzzle now includes summary information to describe the puzzle just played (this is shown at the top).
• In the performance analysis, the analysis at group level now shows the average points for the puzzles in a group, instead of the total points.
• Long help explanations can now be scrolled. This ensures that the explanations are able to fit within the display space available.
• In Random Play, when the setting for selecting the size of the next puzzle has been turned on, a new option lets players choose to see the outcome page of the previous puzzle when Random Play is first launched. This makes it possible to select the size of the first new puzzle to be generated.
• Also included: some cosmetic improvements, a fix to the way the candidate values for empty puzzle squares are determined and more corrections to the help explanations.