Use processing for wrecks

[oh-noey]

Describe in detail what your pull request accomplishes

Wrecks are notably slow at the moment - lets try moving them to processing.

The total duration of wreck fading is the same, however the batching control settings no longer have any sway beyond setting the total time. Fade ticks are now evenly distributed throughout the duration of the fade.

Checklist

• [ ] Unit tests
• [ ] Proper internationalization
• [x] Tested
• [ ] Performance tested