merge changes from monero: translations(PR #4513)

[bleepster]

Merging the following commits:

• Create Japanese file, add translations for "Monero::AddressBookImpl" and "Wallet" Contexts (5c4fe3d4a5973217f866568907af6ae3a9d2c5eb)
• Add translations for Monero::PendingTransactionImpl, command_line Contexts (ee71ba9869c37e92cb56590bb344e6e937d91c54)
• Finish all contexts but simple_wallet, translate 23% of simple_wallet (539debc477a756907a82a45fa3d414e4b1a3b300)

All commits are from PR #4513

See individual commit messages for more details.