"Large Biomes" and "Amplified" are world types instead of "Customized" presets

I don't like inconsistencies and so I noticed that after the "Customized" world type was added, "Large Biomes" and "Amplified" were still their own world type instead of being a preset in the new "Customized" world type. I talked with Ryan Holtz (@TheMogMiner), the creator of the Customized world type, about it and he said that this will change, as both world types only consist of a few parameter changes, but up to now nothing happened. This bug report is supposed to be a reminder that said issue is still to be dealt with.

The initial conversation can be found here: https://twitter.com/MegaManki/status/458583398416924672