This removes the attempt at magic (predicting future) component
called the fee-estimator.
The direct effect is that all transactions have as a mempool acceptance
the same minimum fee. Regardless of how full the mempool or blocks were.
This mempool-acceptance minimum fee is 0 sat/byte. (aka free)
Notice the node-wide free-tx accept-limiter is going to avoid us getting
overloaded.
During the BCH fork-off time we allowed the client to be started
as either BCH or BTC and as such there are several code-paths
that behave different based on this user setting.
We remove those as we no longer allow starting as BTC client.
This also removes the check for the min-block-size (rollback protection)
as this is accomplished by the checkpoints on the BCH chain.
Remove no longer useful options;
* chain (sorry, supporting the btc chain just doesn't seem worth it)
* initiatecashconnections, we only allow Cash connections now.
* flexiblehandshake, same for incoming. Reject non-cash ones.
tomFlowee
TomZ