Pre-release fixes and improvements

The big lines:

* Improved FPS fix
* Fixed R3F towing and helicarrying issues
* Cleaned up antihack
* Added plane spawning
* Improved convoy vehicles selection
* Removed Sport Hatchback from vehicle spawning
* "Water Bottle" changed to "Water Container"
* "Canned Food" changed to "Snack Food"
* 50% chance of repair kit on respawn