- fixed class not found exceptions. we now use string instead of class as a work around due to forge having a broken class loader back then
- added writefree ids config option. disable it once all id conflicts have been resolved. this is to save some load time for HDD drives and like 25ms on SSDs

known issues:
- doesn't restrict the free ids to write 4096 -256 +1 for items, < 256 for terrain gen free ids > 256 for normal blocks