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.
After 122786d0e0, BIP65 activates at
a particular height (without regard to version numbers of blocks
below that height). Rewrite the BIP65 functional tests to take
this into account, and add a test case that exercises
OP_CHECKLOCKTIMEVERIFY in a block where the soft-fork is active.
Also moves the bip65 functional test out of the extended test suite.
