Full unicode support

• Handle unicode as part of meta or message
• Github CI

Robustness at overload

• Report how many messages were dropped due to overload protection
• Print to standard_error when internal message can't be sent

Overload protection, Formatter

• Basic overlaod protection (async / sync / drop modes)
• More error handling (retry on eagain; handle gen_server:call timeouts)
• Offload msg formatting to logger_formatter

Robustness

• Handle some of gen_udp:send errrors (emsgsize, enobufs)
• Handle situation when handler process is already started
• Fix typo in convert_meta guard

Cleanups

• Rename journald_log to journald_sock
• Edoc cleanup
• Some typespecs added
• Copule more APIs to journald_sock
• Github link for hex.pm

Initial release

• Thin api-wrapper to log via /run/systemd/journal/socket: journald_log
• gen_server based OTP logger handler: logger_journald_h
• Unit tests
• Common tests
• CI
• Code formatter and linter
• Basic edoc