This removes the option from the wallet to not pay a fee on "small"
transactions which spend "old" inputs.
This code is no longer worth keeping around, as almost all miners
prefer not to include transactions which pay no fee at all.
(cherry picked from commit bitcoin/bitcoin@ddf58c7573)
Zcash:
* Add release notes.
* Use `UIError` instead of `InitWarning` for the warning that
`-sendfreetransactions` is no longer supported (because we haven't
refactored `InitWarning` to be accessible from the wallet code).
* Update the `show_help` RPC test to remove `-sendfreetransactions`.
Signed-off-by: Daira Emma Hopwood <daira@jacaranda.org>
9a7dc79c08