That way we start waiting on the shutdown event no matter what
so we can always be shut down

This also fixes a recent reorg bug...

Fixes #532

The interface is changing; best to target a single codebase

Make it more naturally async

Spawn separate tasks for each peer we test

Give private methods a leading _
Remove dead code

- Use tuples in preference to lists
They are always at least 11% smaller memory
footprint, r...

Much more efficient to just calculate it outright than try
and maintain datastructures

- highly concurrent and a lot more efficient than previously
- initial mempool sync should be mu...

The mempool as its own process would maintain its own daemon

Clarifies the mempool interface to look more like what it
would in its own process

- enables removal of executor code
- clarify flush guarantees

* Motion added

We used to rely on the daemon being able to return the
orphaned blocks, but some old daemon code...

- reduces the tangle of object dependencies
- rationalizes responsibilities

This helps to rationalize the inter-object
dependencies.

Ultimately this stuff belongs in a ChainState object.

It was mistakenly made a pylru cache...
Don't force non-Dash coins to carry the cache.

- remove the header cache - not needed for higher protocol versions
- simplify session notificat...

(thanks to nijel)

Disable a test that will require significant work

Break out controller functionality for session management.

which better belong there:

- PROTOCOL_MIN, PROTOCOL_MAX
- server_features()
- server_version_ar...

- remove unused self.client_version
- coerce client_name to a str

Cleanest to move the mc_cache to the block processor

Rename function to prevent similar mistakes in future

Also hash_to_str -> hash_to_hex_str

Fixes #523

BU, XT and other coins based on older Core code require integers
not booleans