IItem Renderer Reborn

made simpler names for IItemRendererHandler and IBlockRendererHandler. they were complex due to a tiny bit of code remaining from elix_x naming conversions when they should have been simpler names.
Added a method in IItemRendererHandler to renderOverlay determined based on if graphics are fast or not
cleaned up RenderItemObj code
this update requires all dependents to update their method names as well. Will crash with silkspawners.