Enigma Source (svn, archived)

- replace YieldedGridStone by Stone subclass YieldingStone
- fix crashing on stones that suicide on set or move
- pull stone reengineering:
- renamed to st_pull
- preserve identity on moves:
- can now be used with rubberband and wires
- can be named and attributed
- ensure that pull does not press triggers on both affected grids
while moving
- made light transparent
- swap stone reengineering:
- renamed to st_swap
- preserve identity on moves:
- can now be used with rubberband and wires
- can be named and attributed
- ensure that swap does not press triggers on both affected grids
while moving
- fix brake on shattering actors on pull stone swaps
- fix plain_move and firebreak:
- fall on changing floors