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
Rewrite shp(ts) parsing to avoid offset issues.  Fixes #6822.
Make the legacy editor more robust against invalid templates.
Merge pull request #6824 from pchote/external-editor-templates

Fixes #6812
Merge pull request #6823 from pchote/fix-shpts-offsets

Closes #6020
Merge pull request #6807 from obrakmann/lua-cleanups

Lua cleanups
Add support for per-tile minimap color and height/ramp type.
TileSet cleanups.
Rename TileTemplate -> TerrainTemplateInfo.
Load tmp(ts) ExtraData for cliffs etc.
Work around the undesired R8 terrain sprite offsets.
Convert TS terrain height, ramp, and minimap colors.
Introduce TerrainTemplatePreviewWidget.
WIP: Hook up basic city buildings.

TODO Footprints.
Add demo map used for news screenshots.