Remove print() from core classes #4735

Remove unused print()s and change the instance on CBlock to ToString(). Breaks dependency from core.o on util.o.

Before:

src/libbitcoin_common_a-core.o
  src/crypto/crypto_libbitcoin_crypto_a-sha2.o
    CSHA256::Reset(...)
    CSHA256::Write(...)
    CSHA256::Finalize(...)
    CSHA256::CSHA256(...)
  src/libbitcoin_common_a-script.o
    GetOpName(...)
  src/libbitcoin_util_a-uint256.o
    base_uint<256u>::EqualTo(...)
    base_uint<256u>::ToString(...)
  src/libbitcoin_util_a-util.o
    FormatMoney(...)
    LogPrintStr(...)
    LogAcceptCategory(...)

After:

src/libbitcoin_common_a-core.o
  src/crypto/crypto_libbitcoin_crypto_a-sha2.o
    CSHA256::Reset(...)
    CSHA256::Write(...)
    CSHA256::Finalize(...)
    CSHA256::CSHA256(...)
  src/libbitcoin_common_a-script.o
    GetOpName(...)
  src/libbitcoin_util_a-uint256.o
    base_uint<256u>::EqualTo(...)
    base_uint<256u>::ToString(...)

Automatic sanity-testing: PASSED, see http://jenkins.bluematt.me/pull-tester/p4735_380222411038cb4f74cbb109984c4b855b4799f6/ for binaries and test log. This test script verifies pulls every time they are updated. It, however, dies sometimes and fails to test properly. If you are waiting on a test, please check timestamps to verify that the test.log is moving at http://jenkins.bluematt.me/pull-tester/current/ Contact BlueMatt on freenode if something looks broken.

ut ACK

ut ACK

posthumous ut ACK