Crate actions can now define required prerequisites.
Update mods (only d2k and RA affected) crate actions to take tech levels and prerequisites into account.
Added YamlException to GiveUnitCrateAction if no units are defined.
Make ra light tanks be able to crush infantry to improve usefulness
and be consistent with the rest of the ra tanks and ra1's light tank
Fix legacy map importer. Fixes #6143.
Let ra apc and minelayers crush infantry too
disallow bots on poland raid
disallow bots on burlesca
Update CONTRIBUTING.md
Merge pull request #6212 from pchote/mapimport

Fix legacy map importer.
Merge pull request #6213 from ScottNZ/balance

Update crushing values for ra vehicles
Merge pull request #6189 from UberWaffe/6066_CratePrerequisites

6066 Crate Prerequisites
Merge pull request #6215 from Mailaender/poland-raid-bots

Disabled bots on maps with separate land masses between destructible bridges
Make FMVPlayer in TD use a completely black background

Fixes #6211.
Make FMVPlayer in RA use a completely black background
5936 Advanced Power Plant have a different layout in the original
Merge pull request #6230 from havok13888/AdvancedPowePlant

#5936 Advanced Power Plant have a different layout in the original
Merge pull request #6220 from obrakmann/fix6211

Make background of FMVPlayers in TD and RA black
avoid NullReferenceException in updatedRegion

fixes #6166
Merge pull request #6226 from Mailaender/shroud-updatedregion-nre

Fixed a crash when there are no actors to reveal shroud on the map.