Enchantment Limiter

- negative enchantment points will first lower the cap before positive enchantments are calculated, so you can fit more positive enchantments on in one anvil run and won't have to do weird splitting stuff.

- enchantments now support decimal incremental costs. This can be removed with a bit of config and lang work if it really bothers you. A config value can be set to round sufficiently close values to whole numbers, so you can fill in things like 0.33 for each level of sharpness and have sharpness III round up nicely to 1 point.

- items now support accounting for enchantability. This allows you to have a custom item point definition and still have it adapt to changes in enchantability, however that might happen. It also means you can define how enchantability affects different items, so gold can benefit from added enchantability more than iron as an example (again, however that might happen, generally apotheosis).