Added AI check for winning in 2 actions

- Added checkWinTwoActions
- Also separated out isAdjacentToGoal and moveIntoGoal from
checkWinNextAction (previously were all part of checkWinNextAction -
necessary for checking win in two actions)

This was not done under the watchful eye and guiding hand of Shu, so it
may be poorly organized or styled - refactor or rewrite anything you
like