Let upper-layer APIs like actor.Send() return it as well. Server can return
"already exists" which is an error and yet at the same time a very special
one, in many cases it means we can proceed with waiting for the TX to settle.
calculatenetworkfee MUST calculate complete proper network fee, if we have
some extensions enabled and some attributes should be paid for that they're a
part of the equation too.
Unfortunately Go doesn't allow to easily reuse readers in full packages, still
we can have this wrapper with a little overhead (the alternative is to move
specific methods into types of their own, but I'm not sure how it's going to
be accepted user-side).
Somewhat similar to invoker, but changing the state (or just creating a
transaction). Transaction creation could've been put into a structure of its
own, but it seems to be less convenient to use this way.
They were first introduced in a058598ecc and
then carefully moved in 648e0bb242, but it looks
like they were never used by any external code. This code can be useful on the
server, but the server has its own params package to deal with
parameters. Clients usually create Parameters and then get results as
stackitem.Items, so they don't use this code either. So there is zero point in
keeping it.
