Update b064 minor

Update b064 is live!

This contains some cool GUI additions and stuff. :)

changes

- castle rockets are faster
- effect for when islands and airships regenerate health
- selection GUI display
- can select only one type of unit from selection
- can tell airships to target another airship

fixes

- fixed huge CPU use by airship AI
- fixed airships not reacting to enemies when there are many of them
- slight adjustments to Kip projectiles, enemy spawn rates and some other things