Market sets

I have programmed a new feature and added it to the market page.

Now you are able to create, delete, buy and sell sets.

This way you can create a set with an amount of goods you regulary buy or sell. You simply create a set, buy or sell it and delete it when you don't use the set anymore.

For database overflow regulation reasons, you are only able to create a maximum of 5 sets.

I hope you will like this feature ;).

PS: What do you think about the ability of naming your sets? (Personally, I think that this is an unnecesairy option).