Add option to list the new prices in the API

[klenium]

I don't need to download all prices if 99% of it is the same as my last stored data. Add an eg "last_time" input, I set it to the current_time of the last update, and then the API lists only the newest changes. Less data transfer, faster processing.

[fisk]

Sounds good so I'll consider it.

[Bone]

helpful for me too

[Pearly Gates]

why not

[The Radiated Banana]

helpful for me too

and moi

[Pwndaz!]

That's a really good idea.