Enchant changes

Reenables `enchant` command that had been previously disabled during the switch to Info.lua command registering. Updates the enchant command to behave more like vanilla minecraft, and adds the `ienchant` command to allow only enchanting ones own items (similar to the difference between `give` and `item` commands ). 
To avoid having to check the player name match, use the `DoWithPlayer()` function instead - it only calls the callback on an exact match