Bypass the 4J RenderManager's hardcoded SyncInterval=1 by calling
the DXGI swap chain directly with Present(0, ALLOW_TEARING) when
VSync is disabled. Falls back to the library's Present on failure.
Relocate VSync/Fullscreen setting flags from bits 18-19 to bits 24-25
to eliminate overlap with the render distance byte (bits 16-23).
Sync the Fullscreen game setting when F11 is pressed so the graphics
menu checkbox stays accurate.
Remove tracked DumpSwf.class (already covered by tools/*.class gitignore).
383c710833