dcrjson: add ticket fee field to PurchaseTicketCmd.

[dnldd]

No description provided.

[davecgh]

This is going to require a rebase since it conflicts. Also, why is this field required? The fee is already known to the code and is applied accordingly. There is already a spendLimit parameter which limits how much will be paid for the ticket.

[dnldd]

the field allows overriding computed ticket fees with a custom value, see decred/dcrwallet#406

[davecgh]

I'll take a look, but this doesn't really feel like the correct place for such a thing. I'm pretty sure the only reason this RPC exists in drcd to begin with is to make use of the current ticket price. If the goal is to simply create custom tickets, I really don't think that belongs here.

[davecgh]

After discussing this offline and looking again, its intent is to allow the transaction fee on the ticket purchases to be specified directly as opposed to the ticket purchase price as I commented above. I have no objections to allowing the transaction fee on the ticket to be specified as a part of this call.