Make createmultisig only accept public keys with the old functionality
marked as deprecated.
Splits _createmultisig_redeemscript into two functions, one for
getting public keys from UniValue and one for getting addresses
from UniValue and then their respective public keys. The one for
retrieving address's public keys is located in rpcwallet.cpp
Changes addwitnessaddress's output to be a JSON object with
two fields, address and redeemscript.
Adds a test to deprecated_rpc.py for testing the deprecation.
Update the tests to use addwitnessaddress or give only public keys
to createmultisig. Anything that used addwitnessaddress was also
updated to reflect the new API.
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.
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.
