CODEBASE: Version 2.8 stuff (#1989)

Change dev version from 2.7.1 to 2.8.0

Also adjust the save data migration code for the latest check to use "<"
instead of "<=" to agree with the style of everything else.
(I noticed this due to investistigating bumping the version, but that
happens as part of the release commit so it shouldn't be done yet.)

src/utils/SaveDataMigrationUtils.ts

@@ -528,7 +528,7 @@ Error: ${e}`,
   if (ver < 39) {
     showAPIBreaks("2.6.1", ...breakInfos261);
   }
-  if (ver <= 41) {
+  if (ver < 42) {
     // All whitespace except for spaces was allowed in filenames
     let found = false;
     for (const server of GetAllServers()) {