Space Truck Type-C 2.0, SM v0.19228

This update provides the following changes:

1. Download changed from individual .sment file to a .zip containing multiple .sment files.
2. Example Space Truck Type-C variants added to download for convenience:

• Type-CS: Cherry picker salvager from the Apr2015 Build Challenge Week 1 pack.
• Type-CJ: Radar jammed stealth variant, capable of permajam for smuggling ops. Black-cabbed variant in screenshot.
• Type-CW: Jump Drive model for long range operations. 4 full power tanks are needed to charge the device.

3. All variants updated to utilize Rails-based docking and towing.