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.
This commit fixes the module-level docstrings for the tests and helper
modules in qa. Many of these tests were uncommented previously - this
commit ensures that every test case has at least a minimum level of
commenting.
If node 0 is sufficiently fast to announce its block to node 1,
node 1 might already have the block by the time the
node_sync_via_rpc loop gets around to node 1, resulting in the
submitblock result "duplicate-inconclusive" as node 1 has the block,
but prefers an alternate chain.
John Newbery