Implementing search feature in map choosers
fix broken objectives fine-tuning
Sound Fix for DropDownButton Widget
LoadWidget modRules Fix

Fixes #6625
Normalizing CashTicks AUD for TD
Implement cell triggers. Closes #4400.
Update gdi04c to use cell triggers
Whitespace fixes
Merge pull request #6614 from abcdefg30/fixobj-fine-tuning

Fix broken objectives fine-tuning
Merge pull request #6574 from pchote/celltrigger

Implement cell triggers.
Merge pull request #6504 from s1ww/mapchooser_filter

Closes #6374
Merge pull request #6626 from steelphase-forks/bleed-modRulesFix

LoadWidget modRules Fix
Remove duplicated IronCurtainable rules.
Add a UnitUpgradeManager trait.

This introduces support for timed upgrades, starting with crate buffs.
Fix cloak upgrade expiration.
Reimplement iron curtain as a generic stat upgrade.
Add the invulnerability crate to RA.
Add a GrantUpgradeWarhead and initial TS EMP implementation.
Replace RemoveOnConditions with KillsSelf.

Upgrades offer more flexibility than prerequisites.
Detonate demo trucks when they are iron-curtained.