When running the tests locally with a parallelism of 4 on an otherwise
busy system, RPC can take quite a wait to come up.

Change the timeout to 60 seconds just to be safe.

Github-Pull: bitcoin#11091
Rebased-From: c1470a0

Fixes a couple of bugs from the introduction of TestNode:

- test scripts were no longer able to specify a custom timeout for
starting a node. Therefore tests with nodes that take a long time to
start up (eg pruning.py) would fail.
- the test for whether a node has failed on start up was broken
by changing 'assert x is None' to 'assert not x'. Since
subprocess.poll() can return None (indicating the node is still running)
or 0 (indicating the node exited with return code 0), this was a
regression.

Github-Pull: bitcoin#11077
Rebased-From: 2b4ea52

Github-Pull: bitcoin#11068
Rebased-From: 08ce33f

Github-Pull: bitcoin#10798
Rebased-From: b23549f

Github-Pull: bitcoin#10798
Rebased-From: c6ec435

Github-Pull: bitcoin#10859
Rebased-From: 6d2d2eb

Github-Pull: bitcoin#11150
Rebased-From: 4f2905b

Github-Pull: bitcoin#11121
Rebased-From: be2a2ab

Separates the act of creating a TestNode object from starting the node.
The test_framework now keeps track of its list of TestNodes, and test
writers can call start_node() and stop_node() without having to update
the self.nodes list.

Github-Pull: bitcoin#11121
Rebased-From: 36b6268

Github-Pull: bitcoin#11121
Rebased-From: 6cf094a

Almost all test scripts currently need to override the __init__()
method. When they do that they need to call into super().__init__() as
the base class does some generic initialization.

This commit makes the base class __init__() call into set_test_params()
method. Individual test cases can override set_test_params() to setup
their test parameters.

Github-Pull: bitcoin#11121
Rebased-From: 5448a14

Github-Pull: bitcoin#11121
Rebased-From: 7148b74

Github-Pull: bitcoin#11215
Rebased-From: 3918d93

This patch improves branch coverage of the test, making sure a
message can not be verified with the wrong address or signature.

Github-Pull: bitcoin#11241
Rebased-From: b3d6fc6

Github-Pull: bitcoin#11234
Rebased-From: d1138e3

Github-Pull: bitcoin#11210
Rebased-From: dea086f

Github-Pull: bitcoin#11067
Rebased-From: faa8d95

Github-Pull: bitcoin#11125
Rebased-From: e127494

Github-Pull: bitcoin#11125
Rebased-From: 5c18a84

Github-Pull: bitcoin#11125
Rebased-From: 232e3e8

Github-Pull: bitcoin#11125
Rebased-From: ce379b4

Github-Pull: bitcoin#11310
Rebased-From: fb1f325

Github-Pull: bitcoin#11308
Rebased-From: fadd0c1

Github-Pull: bitcoin#11078
Rebased-From: 0063d2c

assumevalid.py would try to send over a closed P2P connection in a loop,
hitting the following failure many times:

TestFramework.mininode (ERROR): Cannot send message. No connection to node!

The test still passes, but this is a lot of noise in the test log.

Just check that the connection is open before trying to send.

Github-Pull: bitcoin#11345
Rebased-From: e9e9391

Github-Pull: bitcoin#11116
Rebased-From: d7afe2d

Github-Pull: bitcoin#10552
Rebased-From: d3677ab

Github-Pull: bitcoin#11319
Rebased-From: a782042

Changing __init__() -> set_test_params() in the tests should not have
applied to NodeConnCB-derived objects.

Github-Pull: bitcoin#11319
Rebased-From: f97ab35

The LevelDB docs seem to indicate that an iterator will not take
snapshots (even providing instructions on how to do so yourself).
In several of the places we use them, we assume snapshots to have
been taken.

In order to make sure LevelDB doesn't change out from under us
(and to prevent the next person who reads the docs from having the
same fright I did), verify that snapshots are taken in our tests.

Github-Pull: bitcoin#11422
Rebased-From: bb8376b

Github-Pull: bitcoin#11399
Rebased-From: 49f869f

Github-Pull: bitcoin#11407
Rebased-From: 1088b53