Stabilize (part 3)

Ding won the first game! Who would've thought it? ๐Ÿ‘‘ A (probably) last small batch of fixes is here for 0.7.x. Time to focus on 0.8.x ๐Ÿ› ๏ธ [h2]Fixes[/h2] ๐Ÿ”ง Resolved an issue with calculating material differences during gameplay. ๐ŸŽฅ Fixed rare edge cases where key moments started on their own. ๐Ÿ“… Squashed a bug preventing tournaments spanning 2 years from showing in the calendar. ๐Ÿ—“๏ธ [h2]Updates[/h2] ๐Ÿ‡ฉ๐Ÿ‡ช Adjusted the start dates for German nationals. ๐Ÿ‡บ๐Ÿ‡ธ Adjusted the start dates for USA nationals.