Add radio function to read the radio syncword uint16_t syncword = Rad…

…io.GetSyncWord(void);

Add custom Syncword and Low DataRate optimization

Add functions to get network session key and app session key after join

Add missing header file

Fix DR reset with ADR enabled

Fix callbacks for P2P RX and TX timeout not being called

Update examples + README

IRQ_HEADER_ERROR should issue RX error

not RX timeout

Fix public/private network always public

Add option to restart MAC stack to change e.g. region without re-init timers

Add MAC counter reset function