Introduce 2 new daemon logging options: LogUTC & LogMicro.

[lainedfles]

This request adds two new options to configure the daemon logging:

• LogUTC: toggles time.Now().UTC() vs time.Now().local()
• LogMicro: enable microsecond timestamp

Both options are exposed within the UI.

[gustavo-iniguez-goya]

Thank you @lainedfles . For future changes: maybe it wouldn't be a bad idea to group logging options under "LogOptions": {} or something similar.

[lainedfles]

That's a good suggestion. I'd also like to introduce a sub-tab under nodes dedicated to logging.