Issue #1851 shows that a zaddr->taddr can be rejected from mempools
due to not meeting fee requirements given the size of the transaction.
Fee calculation for joinsplit txs has not yet been agreed upon, so
during this interim period, this patch ensures joinsplit txs using
the default fee are not rejected due to an insufficient fee.
Commit 2eeb6b randomized the order of input and output notes,
but this is now known to prevent the chaining of multiple joinsplits
in a single transaction. The root cause has yet to be determined.
This patch is a temporary fix and disables the shuffling of input
and output notes. It also adds a chained joinsplit test to the
python qa test suite.
Extra parameter added to AvailableCoins to include or exclude Coinbase coins.
SelectCoins, used for sending taddr->taddr, will exclude Coinbase coins.
Added qa rpc test and a runtime parameter -regtestprotectcoinbase to enforce
the coinbase->zaddr consensus rule in regtest mode.