improved `isAvailable`, checkes all record structs, inverter becomes available more early because version is check first
fix tickers were not set if NTP is not available
disabled annoying `FlashStringHelper` it gives randomly Expeptions during development, feels more stable since then
moved erase button to the bottom in settings, not nice but more functional
split `tx_count` to `tx_cnt` and `retransmits` in `system.html`
fix mqtt retransmit IP address #602
added debug infos for `scheduler` (web -> `/debug` as trigger prints list of tickers to serial console)
improved wifi initial connection - especially if station wifi is not available #509
removed new operators from web.h (reduce dynamic allocation)
improved sun calculation #515, #505
fixed wifi auto reconnect #509
added disable night communication flag to MQTT #505
changed MQTT publish of `available` and `available_text` to sunset #468
added icons to index.html, added wifi-strength symbol on each page
moved packet stats and sun to system.html
refactored communication offset (adjustable in minutes now)
-> now Ahoy opens an AP during boot. This will be closed once a station WiFi connection is established
improved NTP after boot, will be synced immediately after successful WiFi connection
