Contract Lighter

*Fixes the major bugs in Contract Light
*Lower entry costs to 20x (from 50x)
*Fix pass specifier in Tree.cfg
*Fix RT code for 0.3m core
*Move heat shields to appropriate nodes (big, later ones are moved to Nanolathing for now, it will serve as a "catchall" node for stuff that shouldn't be in the starting nodes but for which we haven't figured out the correct node).

Suggested Play Settings
Hard (with quickload and revert) but starting funds down to ~4000 or so, and fund rewards at 20%.