Tax Free Levels

This is a large rework of the mod, please have a read!

• the "Too Expensive" anvil limit is now removed (by default, configurable)
• new cost calculation bases cost off of level 0 instead of level 30, except for the Enchanting Table, where the cost is based off of the level requirement instead
• new config with level base and anvil limit options
• the config is automatically synced from server to client, fixing visual issues on the client
• (the mod can still work server-only, but you have to live with visually wrong level costs and "Too Expensive")

Quick cost comparison:
In 1.3 the cost is the amount of XP needed to get from level 30-X to 30, having no effect below player level 30 (besides small tax).
In 1.4 the cost is the amount of XP needed to get from level 0 to X, with the exception of the Enchanting Table.
In an Enchanting Table with e.g. level requirement 21, the cost is the amount of XP needed to get from level 21-X to 21.

To restore the behavior of 1.3, you can set the level base setting to 30.

Backports to older Minecraft versions might take a while...