R2006

• enhancement: influx tunable intervals
• enhancement: sntp should use domainname to determine server IP
• enhancement: added support for vacation periods
• enhancement: syslog should use logging infrastructure
• enhancement: reordered startup
• enhancmennt: upgrade to idf release/v3.3 for esp8266
• fix: some MQTT issues
• fix: exit in telnet session may cause crash
• fix: leaking socket
• fix: on holidays only holiday actions should be performed