Refactor some functions in cwevent/cwgame for DRY

[tturocy]

There are some functions for generating the columns in cwevent and cwgame which arguably violate DRY - for example, one function which applies to each of the three runners on base, which differ only in a parameter (1, 2, 3). These could be re-factored so the logic appears once, and is suitably parameterised.

Because there are only three bases, the benefit from this would be minimal - it would not save much code, and after all there are only three bases so it does not really lead to the generalisation that DRY usually would.

This could be a good mini-project for someone who wants a bit of practice refactoring C code and working within GitHub, to make a contribution to the implementation.