Check default/minimal startscript

[sprunk]

If you do spring.exe --map foo --game BAR, or if you run spring.exe and then start a game via the basic script, the engine will generate a minimal startscript. This generated startscript contains MaxSpeed=20 which is the same as the default anyway.

Tasks:

• check if there is more chaff in that startscript.
• remove anything redundant.