Update dependencies and improve build process

[luanpotter]

• Update flame_lint to 0.2.0 (to fix deprecated option warning + more rules)
• Bump other packages (mason, dartdoc)
• Update build script to use mason from pubspec instead of requiring global mason_cli
• Use newer mason to re-generate the binary files (should be no-op, just different format)
• Support old versions of flame implicitly (before you HAD to pick last 3, now we show last 5 but you can pick any)