PRFC: Make Smart Contracts be able to pay their own gas fees.

[chilligerchief]

As the title states, it would be great if smart contracts could pay the gas fees from executing them.

Why: There are use cases, where users want to execute a smart contract but do not have gas tokens (say you just swapped all your XPLL for a PRFC-1 token). If you want to swap back for example, you first have to transfer XPLL from another account.
If the DEX smart contract could pay its own gas fees, it could swap the tokens, and keep a part of the gas to pay for its fees.

In general, this would mean, that gas fees could be paid in any token, as long as there is a smart contract that swaps the tokens in the background and pays for itself and the executing smart contract.

It would be great if this could be added as a PRFC, I can also provide more details on how this could or should work.
Please also let me know if you already thought about such a functionality or are already working on something similar.

[chilligerchief]

@lyulka could you provide some feedback on this topic?