Fixed #621 error caused by signed word expanding incorrectly to an unsigned dword
Merge pull request #626 from duncanspumpkin/fix_621

Fixed staff hire crash
Update readme.md
add RIDE_LIFECYCLE_18 to enum
fix warnings and only allow cheats in play mode
add more cheats to cheat window and a small amount of refactoring
Missing Dutch cheat window strings

As added for English by commit e887311219b3acbe4872744d705902e674978488.
Merge pull request #628 from Gymnasiast/patch-3

Missing Dutch cheat window strings
Labeled peep->sub_state and rejiged next_z
Started peep_update_walking
Added more peep_walk. Fixed waving bug
Added peep lost function