Update a020 is live!

This update drastically changes the way the game is played. Instead of being stuck in one spot you can go and explore different island groups throughout the map.
It is now time for a complete code re-factor, so the next update may be in a week or so.

additions

 - islands now spawn as static sectors, still working on making them balanced though as they are a bit exploitable
 - able to select and reposition several islands at once
 - GUI moved to bottom of the screen
 - added several (but not all) sounds
 - enemies now spawn based on random cells you own (bug: they can spawn on top of you) instead of the view border

fixes

 - cell spread function drastically improved. Can now get 50fps on my crappy laptop with 300+ islands on screen
 - missiles do not collide with neutral islands
 - cost of a lumberjack reduced to 10 wood
 - airship factory is twice as fast (1 per 10 sec)

bugs

 - sometimes, cannot build something despite having the needed resources (from harvesting too fast?)
   //By the way, if anyone can find a way to reliably reproduce this bug and send me their method, I love you.
 - the sector markers are still visible, it's somewhat deliberate. Welcome to beta! :p
 - islands can spawn in sectors where your base is

experimental features

 - enemies spawn based on randomly generating enemy islands
 - enemies spawn proportional to both their own size and your size