Made gdi04c easier to win and added cell trigger guards
Move Utils.Seconds and .Minutes into DateTime global

Also renames Date.IsHalloween to DateTime.IsHalloween
Move Utils.CenterOfCell into Map global
Point out pitfalls in the Lua API documentation
Whitespace fixes
Remove more references to old Lua API

Fixes #6811
Merge pull request #6807 from obrakmann/lua-cleanups

Lua cleanups