Move crypto_tools.py to public_key.py (#330)

silkaj/cert.py

silkaj/checksum.py

silkaj/money/balance.py

silkaj/money/history.py

silkaj/money/transfer.py

silkaj/public_key.py

silkaj/tui.py

silkaj/wot.py

tests/money/test_history.py

tests/test_public_key.py