painful port to 1.21.8. seriously that took a lot of time. good thing is that 1.21.10 should be easy... oh wait - rendering of blocks in world is totally different, capabilities (blocks holding items) are reworked....

• disc racks introduced. i wasn't sure i'd do it even though people requested, but i needed to clear my head from painful porting.

• slight change to toolrack rendering. minor perf improvement, although these blocks are already more efficient than vast majority of blocks entities.

• option to rename containers for no cost (1 xp level is still default)