Changed exception message for duplicate enchantment ids

The exception message for duplicated enchantment ids contains both the class path to both enchantments and the enchantment id in question. 

Example exception message: Duplicate enchantment id! class net.darkhax.testmod.enchantment.TestEnchantment and class net.minecraft.enchantment.EnchantmentWaterWorker Enchantment ID:6

A test mod for this can be found [here](https://dl.dropboxusercontent.com/u/38575752/files/examples/Duplicated%20Enchantmend%20ID%20Test%20Mod.jar) both compiled and src versions are within the jar.