DCore update 1.4.2 (not mandatory)

This is a maintenance release for DCore 1.4.x series, targeting memory management improvements and fixes in daemon.

[IMPROVED] DCore and API

• Daemon - uses OpenSSL 1.1 on MacOS
• Daemon - accepts track-account option also for operation history and message objects
• Daemon - optimised storing of recent transaction objects
• Database API - removed useless text field from response of get_message_objects and get_messages

[DEPRECATED] DCore and API

• Daemon - avoid private-key configuration option in favor of miner-private-key
• Crypto API - use wif_to_public_key instead of get_public_key
• Database API - use get_configuration instead of get_config
• Database API - use list_seeders_by_price instead of list_publishers_by_price
• Database API - avoid using set_subscribe_callback and cancel_all_subscriptions
• Wallet API - use transfer instead of transfer2

[FIXED] DCore and API

• Daemon - correctly update message cache after block broadcast
• Daemon - corrected behaviour of genesis-timestamp command line option

[FIXED] GUI wallet

• Fixed crash when GUI wallet is closed before it has been unlocked

Note for Linux binaries: follow the instructions to install DCore on supported platforms (Ubuntu, Debian, Fedora and CentOS)

Note for Mac binaries: follow the instructions to install DCore on MacOS Mojave

Note for Windows binaries: follow the instructions to install DCore on Windows