This decouples validation.cpp from netaddress.cpp (transitively,
timedata.cpp, and asmap.cpp).
This is important for libbitcoinkernel as:
- There is no reason for the consensus engine to be coupled with
netaddress, timedata, and asmap
- Users of libbitcoinkernel can now easily supply their own
std::function that provides the adjusted time.
See the src/Makefile.am changes for some satisfying removals.
[META] Although it seems like we don't need it for just one option,
we're going to introduce another member to this struct *in the
next commit*. In future patchsets for libbitcoinkernel decoupling
it from ArgsManager, even more members will be added here.
