Bitcoin integration

[dsaveliev]

Merge Bitcoin 0.18.0 to the master branch.

Agenda:

• [x] Make it compile
• [ ] Rebase (and keep rebased) with current master
• [ ] Refactor the locked_chain logic
• [ ] Remove all the TODOs, related to this backport (See UNIT-E TODO [0.18.] tags)
• [ ] Get rid of the compilation warnings
• [x] Get rid of the linkage errors
• [ ] Fix unit tests:
  • [x] blockdiskstorage_tests (see blockdiskstorage_tests.log)
  • [x] proposer_tests (see proposer_tests.log)
  • [ ] fs_tests (see fs_tests.log)
  • [x] rpcwalletext_tests (see rpcwalletext_tests.log)
  • [x] tx_validationcache_tests (see tx_validationcache_tests.log)
  • [x] txindex_tests (see txindex_tests.log)
  • [x] txvalidation_tests (see txvalidation_tests.log)
  • [x] validation_block_tests (see validation_block_tests.log)
  • [x] wallet_tests (see wallet_tests.log)
  • [x] walletextension_tests (see walletextension_tests.log)
• [ ] Fix functional tests
• [ ] Fix lint checks
  • [ ] lint-circular-dependencies.sh
  • [ ] lint-include-guards.sh (https://github.com/dtr-org/unit-e/pull/1123)
  • [ ] lint-python.sh
  • [ ] lint-python-shebang.sh
  • [ ] test/lint/lint-spelling.sh
  • [ ] lint-tests.sh

Signed-off-by: Dmitry Saveliev dima@thirdhash.com