Significant upgrade to encourage spelling

Significant enhancement to encourage players to spell words out, vs. just selecting a first letter then clicking on one of the word icons to add it to the train. With v. 3.2, after an initial letter is selected, second letters that cannot lead to correct spelling of a word in the dictionary are deactivated and greyed out. The player can still choose an available word icon to add it to the train, or can pick any of the active letters to continue spelling. (After each letter added, the set of "valid" next letters is updated.) Once a complete word is spelled it is added to the train. A

A second screen-shot showing  active and inactive (greyed-out) letters after an initial letter selection has been made has been added to the game intro page