- replace JustWifi with a custom WiFi module
- re-implemented Core methods that deal with scanning, directly work with the SDK callback
- re-implemented Core method for opmode to avoid dealing with the 2.7.x pseudo modes
- re-implemented Core method for forced-(modem)-sleep (with the intention to merge with OpmodeNull... todo)
- disable reconnect and autoconnect from SDK, avoid unintentionally storing ssid & pass for these and
  make connection routine watch for events instead. timeout is implemented as a local timer
- do not store runtime data that can be retrieved via SDK calls
- settings are loaded only when starting AP or STA, networks are no longer kept in memory
- settings STA ssidN must be unique
- remove char buffer from the event callback
- trigger station-disconnected event when actually disconnected, not when connecting or explicitly requesting it
- generic rssi sorting method for initial connection, do rssi checks while connected to find a better network

Drop (temporarily?) wps and smartconfig. Both are implementable with the new approach,
but come with some weird expectations from the SDK side (no extra heap with wps, broadcasting plain-text
passphrase with smartconfig, storing station config implicitly, etc.).

Both are sort-of fixed with RTOS SDK, but it is still a big question of whether to support them at all in the current state.