Aerosub 2024-06-04 - waves and swarmers

This first update to Aerosub includes several features that were *almost* ready for the initial release, but weren't quite there.  Some of these are features you have asked for.  This update includes:

• "Waves" now escalate with increasing numbers and stronger enemies.
• An "allies" upgrade recruits fighters to escort you.

• A number of other upgrades, including ground effect and base repair.
• Several new enemy types will appear in the 2nd wave and onwards, including one that fires a swarm of seeking missiles.

• New currency types, although you may not see them, and can't use them for anything yet.  This is a step towards having a reason to explore the deep ocean.  Eventually, repairs will only be possible from non-renewable/non-farmable resources.
• A number of invisible changes, such as changes to intercept behavior.

In addition, I removed some things:

• You no longer starts with default allies and turrets.  Might change my mind about this later.
• Removed the "radar" upgrade.  It will return when I implement it.
• Removed the Windows build.  I'll bring it back if anyone wants it.

Hoping to update weekly, but we'll see!  Please leave your comments and suggestions, and I might implement them!