Add arrow grid to WindMap.

Now you can see the wind map in action. Of course, the event overhead is
incredulous... we probably need to rethink how we're using (or
dispensing... or both) events.
Merge branch 'windAlternateVectors' of github.com:dreac0nic/nimbus into windAlternateVectors
Fix two merge induced errors.

A constructor parameter mismatch
and a repeat bug of using the wrong vector to create wind current arrows.